If by "port over stuff" you mean play your games, then you generally are going to do the same thing you would on Windows - go to steam, click the game, and click install. 98% of my library that I have tried playing since switching to Linux worked just that easily. A couple of games that I bought in early access or as soon as they released, I went into the properties for the game (in steam) and changed the compatibility setting to use "Proton Experimental" instead of whatever the default version was and then they worked fine. Disclaimer I do not play games that require kernal anti-cheat and have not for several years on principle. Many of those do not work in Linux as an active decision to block by the developers.

Now, if by "port over stuff" you are meaning you want to move your save games and the like, they might be a little trickier as the file paths will be different on Linux than Windows (because you don't have the same OS file structure). You can usually find where they need to go relatively easily, and if you have been using cloud saves in Steam those should come over just fine without doing anything.