I'm looking into starting WarHammer 40k, and I combed through advice related from other posts over the years. Found a faction that I vibe with and their aesthetic (Necrons). Additionally, I started to read through the Core Rules and their codex found in the sidebar as well. I just have a few questions related to the 9th -> 10th edition change.

Will figures that I buy right now (and could potentially be 9th) be legal in 10th edition play? Does the rules/codex changes merely change the 'stats' of the figures? Are there any Necrons I purchase that won't exists/be legal in the rules in 10th? (Idk, say an older figure isn't 'supported' or w.e.)

Pardon these questions, I come from a Magic Background and there's a concept of rotation from that game and I didn't know edition changes were the equivalent.

I notice that a '10th ed' Combat Patrol is slated for winter of this year for my skeleton robots, would I be better served waiting for that or acquiring figures right now?

Cheers for any responses.