This sounds a bit 'chicken and egg', but I was invited to join the West Midlands Regional Target Shooting Squad after having a few reasonable results at some shoulder-to-shoulder 'open' matches.

I don't know if there is an equivalent squad in your region, but getting your name and face known might guide you in the direction of a coach/squad.

My first experience of any shooting competition was when a friend persuaded me to enter the British open at Bisley with my Gamo Compact in class 'D'. I was bricking it, but scored better than some of the other shooters with £1000 pistols and more experience.