AR-15s

Don’t mean to offend you but if you aren’t shooting hundreds of rounds a year or thousands than you probably could use some practice. Ammo isn’t cheap but I’d say there are some things worth spending the money on. I am not a great shot by any means and I certainly need more professional training and I am going out around 3 times a month. One way we keep cost down is running timed drills. Drawing and reloading drills can be done with as little as two rounds. Load one round in two magazines and go to town.
If you want to become a better shot and shoot better under pressure situations, I encourage you to search out local clubs holding NRA/CMP Highpower matches and get involved. Actual required equipment is essentially a rifle with scope or irons and an sling and a few magazines. You can invest in a lot more, but a minimal investment gets you started. Course of fire varies based on the particular match and it may be full distance or reduced course, but you shoot slow fire standing, rapid fire sitting, rapid prone, and slow prone. Rapids require 10 shots in 60-70 seconds and require a mag change. Slow fire is single load. You learn a lot about yourself and your equipment. With the right rifle and good ammunition you can get involved some of the long range games, which tend to prove that it is the Indian and not the arrow.
High power rifle - Wikipedia
Three-gun is another fun game to hone your skills. My club does it pretty informally without a lot of running around.