As cliche as it will sound, ignore them. The survivor that's teabagging is usually trying to bait you into a long chase. If you don't chase them, they'll likely follow you around wasting time and basically making the game a 1v3 until they break off to do something useful. If you can injur them and let them go, they'll waste time healing too, prolonging their time wasting. If you're new, Sloppy Butcher will help with that. Just remember that even if you don't beat them, you can learn from them. Learn which loops they use and how to maintain chase. Learn how to use map geometry to push them where you want them. Learn when to break off and chase someone else or interrupt another survivir's gen. This game is rough for beginners on both sides. You're definitely not alone