Are you talking about the lee loader that says you have to buy the rubber mallet to go with it? I think this is the one you’re talking about: https://www.amazon.com/LEE-PRECISION-90254-Classic-Loader/dp/B00162TIXG. They are saying that it may not work for auto-loaders, because it does not full length size the brass. A revolver or bolt action gun usually completely seals and supports the case, and doesn’t require moving it like an auto loading pistol does. Glocks are notorious for not fully supporting the chamber, which leads to a bulge at the bottom, which if not dealt with, could lead to rounds that will not chamber properly. As for using that type of kit, I would probably hold off, and if you didn’t want to invest a ton of money, I’d buy the hand press and a set of dies, and the other related materials. https://www.amazon.com/LEE-PRECISION-90254-Classic-Loader/dp/B00162TIXG
Or, if you have the space and money, save up for a more permanent style press. Personally, I use the lee hand press, like the one in the second link, I use it for 10mm, and have loaded thousands of rounds with it.
The only thing that you actually need right away is a set of dies for whatever caliber you're going to reload.
If it's a bottleneck case, you'll probably need a way to trim them from time to time. Lee makes some cheap ones. If it's straight walled pistol cartridges that you're reloading, trimming probably won't be necessary.
Having a way to clean cases can be important, especially if you plan to switch to another lube later. The one that comes with that kit is water soluble, so you can just toss the cases into a container with some hot soapy water and give them a good shake/stir. The best option is a wet tumbler with steel pins like the one Frankford Arsenal makes. Again, if you're using straight walled cases (and carbide dies, which are pretty standard for those cases) then you won't need lube and cleaning is 100% optional unless they're muddy or something. Just a quick wipe with a rag will do fine.
A digital scale is nice to have to double check the case weight before/after adding powder just to be sure. I use this one and it's nothing fancy, but it gets the job done and was cheap. Otherwise you can also dump powder onto the scale that comes with it. Some powders are super fine and bounce around a lot, so I try to avoid that.
And there's a never ending list of other things that you could buy. Just keep in mind that people got by just fine using these for many years with no other accessories other than a hammer and a rag for wiping cases. It's up to you to decide how far down the rabbit hole you want to go!
EDIT: Oops, almost forgot. A good pair of calipers. I prefer digital because you can re-zero it at any point to measure a different in distances. But dial calipers work too. You need a way to measure the finished cartridge to make sure the bullet is seated to the correct depth.
That makes total sense...I am not too worried about the process/time it takes yet. I am more worried about it working for my semi-auto pistol. It says in the description, it is not made for use with a semi-auto, but the reviews claim otherwise. What do you make of this?
for reference, this is the one I am referring to: https://www.amazon.com/LEE-PRECISION-90254-Classic-Loader/dp/B00162TIXG/ref=sr_1_2?dchild=1&keywords=lee+9mm+hand+loader&qid=1593931931&sr=8-2