ridesharing

Hi everyone, I’m going to Europe this summer and I’m not buying a Eurail pass because it doesn’t make sense for my route, so I’m wondering about the feasibility of ridesharing or hitchhiking in a few places to ease budget strain. What countries are best and worst to hitchhike in? Can you generally rely on rideshare/hitchhiking to get around somewhat efficiently? And please no rants on hitchhiking dangers, I’m taking that into consideration too. What websites are most commonly used for rideshares/carpooling across Europe?