what are some options for systems that my friends and I can play for multiplayer tabletop wargaming, preferably either fantasy, star wars or 40K

My friends and I have recently expressed an interest in learning a tabletop wargame whether it's 40K or something else, but I'm new to TTS and don't really know what to look for to get started. Also a lot of wargaming stuff I see is 1v1 and I'm looking for ways that we can play in groups of 3 or 4.