How exactly do terminals work?

I plan on taking an all domestic, all delta flight. I was curious if airlines had organized terminals like say one for my delta domestic, one for delta international, SW domestic, so on and so on. I wish to know if this means i could keep layovers shorter considering I'd be dropped off in the same spot that I'd leave from

Are Lufthansa seat reservations required?

First time flyer, flying with Lufthansa, and noticed there are seat reservation options after booking my tickets, but do I have to actually reserve a seat to have a seat on the flight? Or will they randomly asign me a seat based on what's available? I've tried contacting them but never heard back, my flight is next week and just wanna make sure I'm good to go!

Is it true a day care can't be around a airport?

I work right next to an airport and my co worker has to pick up his daughter far away because no one can build a day care around an airport within a certain distance.

I didn't call on his bs because it may be true. Just another dumb government law that doesn't make any sense? Children can go inside airport of all ages and even on the airplane so why would it be illegal to build a day care near an airport? An airplane could hit my building possibly and if that's the reason that's pretty stupid

First time booking through trip.com and my flights are with Scoot and Cebu Pacific Airlines. I'm unsure where I can checkin and put add ons?

Is there an option to check in and add some add ons through trip.com or directly with Scoot and Ceb Pac? However, I tried managing my bookings separately on their respective websites but they both say they can't find my booking or whatever… My flight is still in a month but I d like to worry about it now than when it's nearer and I doubt they won't appear there because I've had flights before that I was able to add to my manage bookings months ahead.

Must I change terminals or do anything else while traveling the same airline the whole journey?

I plan on taking an exclusively Delta flight from Birmingham Shuttlesworth to Bangor international and I'm worried about having to change terminals or go through security again when i stop for my layovers in Atlanta and JFK International, or if i can keep layovers shorter by being able to remain in the same terminal through the whole journey. Thank you for your time and help, and have a great day!

Going on a plane for the first time tomorrow. What to expect?

I'm going on vacation tomorrow and will be flying for the first time. I'm flying from NJ to Florida. I'm not scared about the actual flight but I'm very OCD and worried that I will hit long lines in the checkpoint and end up missing my flight. So what can I expect at the airport and how can I make my process as smooth as possible?

I'm arriving 5 hours ahead of my scheduled departure time. A little overkill, I know because they usually recommend you arrive only 1-2 hours before a domestic flight. But being the planner I'm I like to arrive way early so I can clear the checkpoints first! I'm not bringing much, either. No electronics (besides my phone) and only one bag of mostly clothes and personal products which I will have checked.

How does bag checking work? Do I just give them my bag and go through security then the boarding gates or do I have to wait with my bag while they look through it? I have nothing important in there so I don't mind just walking away. All I want is to get on the plane and get to my destination on time! I'm wearing slip-on shoes, gym shorts, and a t-shirt through security so no removal of laces or belts.

So considering all of this, how long do you think it'll take me to clear everything on time for my flight?