I am not a pro. I did get paid to be a part time precision shooter for a stint. First would be reading some quality books on shooting skills from proper hold, equal/repeated pressure, trigger pull, cheek weld, and overall basics on shooting accurately. Then try to get some hands on help from someone who can interpret and teach skills. Just because they are a good shot does not make them a good teacher. Look at a quality PCP air rifle ($4-600) and I would suggest a 22cal. A 22LR bolt gun is even less expensive for the gun just more per shot. My PCP is more accurate than any of my 22's (non target)
Brief intro: Start close 50' with single step fundamentals with no shots and eventually single shots....lots and lots of reps. IE: From a rested position, bench/prone eyes closed, mount the gun into a shooting position, pause then open eyes and check sight picture. Not where it is perfectly in the "bullseye" just the overall sight picture you get on an easy to see target. Does not matter where it is on the target it should be full, clear, and comfortable not fighting to get a good sight picture. Next, add in aiming in on a target after proper sight picture, and adjust body so you can close eyes completely relax, open and still be on target. This requires body alignment and proper and equal/repeatable grip and pressure with all fingers. (that is just proper mount and sight alignment steps) Then you have breathing, trigger control, follow through and have not fired one live round yet.
Those I have instructed get to shoot some no matter what just for the experience and enjoyment. The shooting is key and working on those skill steps in the shooting. Fun shooting is great just remember now is the time to instill the base stones and bad habits can be base stones almost impossible to move.