Are carry ons checked at the airport?

I feel that this is a stupid question. I'm 17 and I've never been on a plane or anything, and I'm going to be alone traveling really far and I don't have anyone to help me… I know the basics of what I can take, but I only want to take a back pack to have with me at all times. That means I'd have my clothes in it too, along with probably pads/tampons. I don't know how carryons work, but do you have them check the whole thing? Do I have to pull everything out? Am I allowed to take two carryons or does that cost more? Can I bring a purse and a carry-on or would that count as another carry on? Sorry I feel this is stupid, but I really have no clue.

Yes they are checked. They tell you to put it through an x-ray machine. If they see something they think is suspicious, they will ask you to.open it up.
Usually only one carry-on per and a personal item per passenger.
Your purse counts as the personal item.

There's normally a strict size limit for ONE piece of luggage which may accompany you into the passenger area of the plane. This is generally smaller than a back pack would be!
Other stuff is checked in as luggage to go in the cargo hold of the plane. They will not make you pull anything out of that, they just put a label on it an stick it on the conveyor and you see it again at the other end of your flight.
Your hand luggage is likely to be scanned, if they see anything which puzzles them on the scan, they will ask you to show what it is.

Ok here is how it goes. Checked bags are taken at the gate and placed on the airplane. When the plane lands those bags are move to "baggage claim" where you pick them up. Follow the crowd, they are going to baggage claim… Some airlines charge a fee for checked bags. See if your airline does charge this fee…

A carry on bag is a bag that you take with you through the security screening process. It has to be small and fit in an over head compartment. Your airline will have a maximum size that a carry on can be. Again check with your airline about the allowable size. Chances are the size is 20 inches by 10 inches by 7 inches. If it can fit in that space then your good to go. If your at a luggage place, ask to see what they call a carry on sized bag. That is the size of the bag that will fit in the overhead compartment. If your backpack is similar in size to the carry on roll bag, then it will fit in the overhead compartment. Now you get two carry on bags. The other one is expected to be a purse or small computer. One goes over head and the other can go under the seat in front of you if there's no space over head. Lastly there are carry on sizes for domestic flights, and a smaller size for international flights. Know where your going and you will be fine. Lastly, if your bag is too large for carry on as determined by the gate staff, they will check it for you and put it under the plane. So either way, your bag will go with you.

You don't have to check a carry on bag if it's within the limits of the airline and they can vary. What airline(s) are you traveling on? Then I can help you better. Your carry on bag has to go through security, the only things that you take out are your bag of liquids and laptop if you're traveling with one. There may be other requirements or limitations depending on where you're traveling from and to. More specifics is helpful.

It depends on your carrier (number of carry-on bags). Their website will have this information.

Liquids are more of an issue than sanitary napkins. Any electronic device larger than a phone has to be removed so if you have a tablet/e-reader that will have to come out.

Clearly: A true backpack is too big for a carry on. The day packs (nerd packs) that Americans are so fond of these days would likely qualify. Basically, an allowable carry on is about the size of a full sized desk top computer CPU or a bit more. Yes, you can take things out at security but you can't have secrets. You can take them away from the X ray, but not from inspection.

Basically you are mixing carry on with checked luggage. The fact you are travelling a long way but don't appear to know very much is rather worrying. Carry on is not designed for you to take everything, just essentials that you need in flight, and possibly a weekend trip, but not long distance where you are going to stay for a period of over a week. You will need checked luggage for your clothes, large volume toiletries such as shower gel, shampoo deodorant etc. Read up on the link below from British airways, but preferably visit the airline's website you are travelling with to get the true information on what you can carry on vs check in.

It depends on the airline. Some will allow a small roll on suitcase or medium backpack plus a "personal item" which can be a computer bag or ladies purse/handbag. The airline will might check it for size and/or weight depending on their regulations and depending how difficult they feel like being on that day. Some airlines allow one piece only - no exceptions no personal item. Some will charge you if you want to take a small extra item so it's a bit of a minefield. Check the airlines rules. Security will ask for things such a laptops to be taken out and scanned separately. This is completely separate from any check the airline may do because of weigh, size or number of pieces. Liquids are limited to a resealable one litre/one quart plastic bag and each item in it must not exceed 100 ml. Larger liquid and gel containers have to go in checked luggage. They will not normally ask for you to take out sanitary pads Some people try to get all their luggage into their carry on to keep from having to check luggage into the airport hold. Checking baggage takes time and some airlines charge extra for it.

What you can take on board (number and size) will vary by airline. Check your airline website for those details. I often take a small rolling duffel and a medium tote bag on board with me. On most major carriers, you can take an item for the overhead and one for under the seat in front of you. There are size restrictions, which vary by airline. On some discount carriers, you can only take a small personal item for free.

Your bag(s) will go through an x-ray scanner at security. They will not ask you to take things out unless something appears suspicious on that scan. If you have a laptop, it will have to come out.

You need to also be aware of the liquid/gel rules for a carry-on - containers can be no larger than 3.4oz/100ml and must all be placed in a single clear 1qt ziploc baggie. You are limited to one baggie of liquid/gel items.

Yes.