Do you remember what you played, what you liked about it? I highly reccomend some research into that so you don't end up with something you don't vibe with.
Almost any precon is a good starting point! MtG has controversially been doing a lot of decks for other IPs, so it would be worth it to get a deck (or set) of your fave IP, if that's FF, that might be the move.
Decks last literally as long as you're interested in playing them. My first commander deck (a ship of theseus) is over a decade old, and I still love to play it!
For accessories, you'll need 100 sleeves, Dragonshield is my go-to, a deck box, and numerous D6s to represent counters. Life is usually measured by phone app in the modern day.