I've been reloading for just over a year, and have become pretty good at it by reading, listening, taking in a few videos, talking to other reloaders, and trying what I learned in small batches at a reasonable, measured pace. I was not fortunate enough to be able to take a class or actually go hands on with a mentor/tutor.
I load only on a Hornady LNL single stage press, but once I have everything set (which itself takes way less time than when I first started) I can prep, prime, and load as many as 60 per hour (from fired, tumbled brass). Not impressive, but fast enough. I am not racing anyone.
I started on .38SPL, and it's still my favorite to load. Low pressure, very forgiving of early goofs. A great cartridge on which to learn and tremendously versatile once you know what you're doing.
Load small batches, and try them out before going large. In a year of doing this, the biggest single lot in my log is 150 rounds. That was a .40S&W load that I had tried out thoroughly.
Pay attention to your pace. Wear safety glasses. Don't take shortcuts. Check your powder charges twice. Don't be tempted to start with anything close to max loads. Log everything.
Last word: none of what anyone tells you matters unless you commit to watching what you're doing and following proven recipes.