The single-shot or bolt-action .22 rifle is, without a doubt, the best starter firearm. It is easily adapted to by new shooters, is an excellent "hands-on" firearm during the initial stages of training, and is a bit safer than auto-loading .22 rifles. Excellent firearm for learning such things as sight radius, sight picture, proper breathing, proper hold/grip, and maintenance procedures. It also allows the new shooter to achieve better accuracy (my opinion), which is definitely a confidence builder.
Many competitive shooters "warm-up" with .22 firearms before getting to their serious matches.
Overall, they are "more bang for the buck", and while most new shooters want to "spray" with .22 auto-loading rifles, accuracy is much easier to achieve if it's done in a methodical way, and with trigger SQUEEZE, not rapid-fire PULLING of the trigger.
Lastly, I still have my very first firearm....a Winchester model 69-A, which is a bolt-action .22LR rifle with a 5-round detachable mag. Since I'm now 59 years old, and it was presented to me on my 6th birthday, it is now 53 years old....but STILL looks fresh, STILL as accurate as it was when it was new, and has greatly increased in its re-sale value (I still have the original bill of sale, showing that it cost $14 back in 1952. Today, it is "priceless"
.....at least to me!)