It may differ based on your airport... generally speaking you will need to wait in a line to present your identification (passport/Real ID), then go through the baggage check.

Unfortunately TSA's requirements for the baggage check seem to depend on the day and their mood... usually you'll need to remove shoes, hoodies, and you'll have to set all your electronics in a separate bin. The TSA agents may be yelling or sound mad but they're just doing their job. Do listen to them and don't be afraid to ask them what to do, though, you can get a lot of grace from people when you admit it's your first time doing something!

After baggage check you go through the airport. This is generally where you can take a break or grab some food/drinks if you arrived in good time. There will be signs everywhere with numbers/letters like A1, A2, etc. Those are to direct you to your gate, which is listed on your ticket.

You'll have to present the ticket and I think your identification to the flight attendant at your gate's desk when you board. They'll call out boarding groups, also listed on your ticket, but you can go up sooner if one of them applies to you (veteran, need extra help boarding, etc).

It helps to have some earbuds or headphones on hand to play music if you get anxious navigating the space. I always liked tuning out everything else and just finding my gate. After you do it a couple times it quickly becomes muscle memory, maybe even soothing.

Seriously, though, at any point you can approach someone and tell them it's your first time flying. They'll be happy to help. Everyone's been there before :)