Time wise, how early should I check in for my flight?

2 or 3 hrs early.

Domestic Flights: At least 2 hours early

International Flights: At least 3 hours early

You'll never know how long it will take you from check-in to your gate

You can check in about 24 hours before. If you're flying coach there are usually people who are automatically checked in (usually this is for people flying first class or business class) and they often get put in earlier groups for boarding. Most of the time the sooner you check in the faster you get to board-because you're assigned to a group that boards sooner. Though I've forgotten to check in before and had to at the counter when I was checking bags. However most people tend to check-in earlier rather than later.

Call and check with your airline. Check n times for domestic and interrnational have changed due to world events and specific conditions at any given airport.

I don't know.

2 hours prior to flight for domestic flights 4 hours for international

you can check in using your phone or computer starting 24 hours before departure. it's best to check in early as many airlines will bump the last person who checked in if the flight is oversold.

you need to be at the airport at least 90 minutes or 180 minutes before an international flight. this is especially true if you'll be checking bags.

being that it's one of the first flights of the day, the ticket counter won't open until 4 am more than likely.

so it's really up to you as you know how long it will take you to get to the airport.

you can check in online and the phone and still check bags at the airport

This does depend on the airport.

If you're flying out of lax, then at least 2+ hours before your flight.

For smaller airports, an hour and a half for a domestic flight.

https://www.tsa.gov/

At least 90 minutes before the flight. Better still is two hours before a domestic flight and three hours before an international one.

So...be there by 4:15 and bring a book to read while you're waiting.

Rule of Thumb: At least an hour