Extremely self conscious

Can someone give me some tips on how to become more confident please? It’s really getting me down that I can’t get out of my comfort zone. Ive ordered some new clothes to change up my style but I’m honestly the most self conscious person ever. Not looks wise but body language/ shyness/ overthink everything I won’t dance or sing around anyone not even myself and I avoid anyone I can because I have 0 confidence how do I get out of this because it’s actually making me feel like I shouldn’t be here.