I try to open minecraft but it either gets not responding every time, or I try to join a server and get "Not responding"

I try to open my minecraft, it get's stuck on the loading screen. If I open it by administrator it opens but then when I try to join a minecraft server, I can't join because it gets stuck on "Not Responding" when it gets to Loading. But If i use the old launcher I can join but I can't see any skins.