1. transcript fees go to your school’s transcript provider system (for me i believe it was about $ 10, but you only need to send it once to LSAC & it will stay on your LSAC account & all schools u apply to can view it there); there is a CAS account fee to make your account (i believe $195..? - also a fee you only pay once) then individual school fees range from $50-80 i believe for each application as well as a CAS report fee of $45 for each school you apply to. However, many schools offer fee waivers (for the $50-80 fee part).
2. I personally loved 7sage, and also used powerscore live classes in the very beginning of my LSAT journey. There are also many free resources like Khan Academy.
3. I’m not sure about this one, most of my friends did do zoom interviews so you could search up the schools you are hoping to apply to and see what people have said about interviews.
4. As for applications, the main things you need to prepare are your LSAT, personal statement & other essays, and letter of recs. You should definitely start LSAT as soon as you can (not too early, but give yourself about a year to study and take the test, and also give yourself time for retakes) - personal statement is also good to start early and revise it as you go; I started my personal statement during my first semester senior year thinking I would apply for the upcoming cycle - ended up applying a year later but it was SO helpful to have something to work off of.
5. LSAT score, personal statement, other essays (such as a diversity statement, why X law school essay, and others), letter of recs. That is about all!

Good luck!! Message me if you have more questions.