Haven't played quake since arena back in the days. Is the playerbase healthy enough to find matches on?

is there any resources or servers for brand new players to learn?

Fair warning, alot of people are not gonna like what I have to say, but what I will say is undeniably true. Games like Quake, Unreal Tournament, well any competetive shooter now a days, is Pay 2 Win and here's why: 60hz is plenty enough to play any single player game with no issues, even games like Serious Sam with hundreds of enemies being thrown at you with no lag or hit detection issues, however you will come to find any multiplayer game that is even remotely popular & has a competetive scene, you'll s...

Have had this obnoxious input lag for years when playing QL, is it solvable or is it a result of using Proton?

they would ban u from the server, then threaten u with the quake mafia.