If you don't care about the eras, start by jumping in to a character that interests you and then branch out from that hero/team and try to follow the creators' other runs. I like collecting eras like this to fill out the chronology of the universe over a certain period, but if I had to guess, most members of this sub don't care about eras/events like this and just enjoy collecting well-regarded runs written by creators they like. There are loads of pretty entertaining events sprinkled in like Avengers Disassembled, House of M, Civil War, Annihilation/Conquest, War/Realm of Kings, Messiah Complex, Secret Invasion, Siege, Children's Crusade, Fear Itself, AvX, Infinity, Original Sin, AXIS, Spider-verse, Time Runs Out and Secret Wars. If you just wanna read Secret Wars you can. In my opinion 1998-2015 starting with the Marvel Knights imprint and ending with Secret Wars is a really great era with a mixture of classic-feeling and modern-feeling runs (Marvel Knights Daredevil leading into Bendis/Brubaker runs, Abnett & Lanning's Modern Cosmic Saga, X-Factor by David, Bendis' New/Mighty/Dark Avengers runs starting with Avengers Disassembled (mostly OHCs for now), Hickman's F4 + Avengers, Uncanny X-Force, Wolverine & The X-Men and then some Marvel NOW! runs like Thor by Aaron, Superior Spider-Man, Daredevil by Waid, Uncanny Avengers, Hawkeye by Fraction, Young Avengers by Gillen). The comics that weren’t or were out of print were read on the Marvel Unlimited app Definitely Google reading orders for specific series as they tend to jump around the place but Google definitely helps narrow it down.

Thor by Aaron Vol 2 (1 is set before Secret Wars), Venom by Cates, the upcoming Immortal Hulk and the inevitable Daredevil Zdarsky Omnis would be some highlights since Secret Wars in 2015. Why do those eras in particular interest you? Just because they're the most recent main eras? In my opinion there haven't been that many good Marvel Omnis set post-Secret Wars yet.

Secret wars omnibus hickman