Only tangentially related (but related just the same...) I love to recommend the .38 Special as the best place to start for -any- handloader's first ever foray at the load bench. I personally believe that while many cartridges are a fine place to start the hobby, there simply are none better than the .38 Special... even more so if the new handloader plans to load them for use in a solid .357 Magnum revolver.
.38 Special brass is common and easy to find, it lasts nearly forever and you don't ever lose it unless you are shooting an odd duck like a S&W 52 or a Coonan. (I shoot a heapload through both)
.38 Special published load data is perhaps as/more plentiful than any other cartridge across the board. Powder selection is huge, bullet selection is huge and for handloaders, it's irrationally popular... so there are many hobbyists happy to share experiences.
.38 Special is (comparatively) a significantly lower pressure round than 9mm, .40cal, .357 or .44 Magnum, and this makes your use of the internal space FAR less critical than it does in a high pressure and small case round like 9mm or .40. And even with a low pressure round like .380, the tiny amount of internal space makes your use of it critical. Careful to never get lazy about this (as it's extremely important!) but in .38 Special, it almost hardly matters.
Being a revolver round, you can focus on getting your feet wet with an easy to work with round that doesn't care if it's loaded light or heavy and doesn't mind what bullet weight you wish to use. It's not subject to any feed or ejection cycle, which sometimes throws new handloaders a curve. Also an advantage with .38 Special in a revolver is that crimp isn't nearly as critical with a typical .38 round like it is with a heavy, big bore magnum revolver round. Not important for a proper and even powder burn and typically not important for bullets that may wish to jump-crimp and lurch forward out of the case.
When run in a .357 Mag revolver, you have a platform that was wholly designed for TWICE the pressure you'll be running (and proofed for even higher.) Not that you should look at this as a safeguard against being stupid, but it certainly is a nice insurance policy that will almost certainly be mental and never needed. But this is no bad thing!
.38 is extremely easy to full length size, flare and seat bullets. Sure... most are! But you'll find a few that are much more obnoxious. 9mm and it's tapered case.. .30 Carbine is truly awful... and any bottle-neck rifle round takes a whole different kind of process for full-length sizing. This isn't a huge factor, but it is real.
Ever heard someone say "it's inherently accurate!" Well, this is debatable for sure, but the .38 Special has a long and distinguished pedigree and it also has a couple physical features that certainly help. First is that you'll most likely launch them from a revolver, which typically has a fixed barrel. While many semiautomatic pistols can be highly accurate and repeatable, there is a reason that rimfire pistols are often so accurate, and that is due to a barrel that NEVER ever moves in the frame and revolvers are the same way. On top of that, the .38 Special tends to be a l-o-n-g bullet, for a handgun cartridge anyway, and you get a lot of bullet bearing surface, and this often translates to accuracy. So when a brand new handloader builds his first ammo AND that ammo drops in the X-ring when he does his part... well, there's a whole lot of confidence that builds quickly and leads to a fantastic experience in handloading, and just feeds in to more and more of it.