You just have do do it again and again, untill you get comfortable with it. Let me tell you my story. First month in univesity i had to present a project for 80 students and 5 professor. I was so nervous and was thinking how would they understand me. But one day before i just said fuck it what happens happens they can't fail me beacuse of my stutte and beacuse of that i was calm. I stood there and presented infront of everyone and I stutterd like crazy, but i when i got more comfortable it got better. People aplaued for me and they aksed me queations about what i talked about (they understood me). You just need to get out of your own head. Just fucking do it... Are you nervous asking for help at a store go to every fucking store and ask for help.