Which multiplayer system for a racing game?

I am making nice progress on my racing game and before I get too far I would like to get multiplayer working. I have never done multiplayer before so have next to zero experience with any lib apart from Direct Play many many years ago. With Unity changing its system and there being so many different options out there what would be the best fit for a racing game? Would like it to work across all platforms and be easy to use. I have looked at Forge, Photon, old UNet and a few others but I am a bit dazzled by the new terminology.

 

Your question is a bit too open ended. You should decide what "all platforms" means to you, and what network architecture you want for your game, and that will narrow down the field for you.