Your first step should be to get all the loading manuals you can afford to buy, I would recommend a minimum of three. This is important because each manual comes to its data from a slightly different direction, and it is useful to be able to make comparisons. Occasionally there are mistakes that you might encounter, so it is valuable to have more than one source of information.
The press is the center of the handloading process and to start I think you are best to choose a single stage press. If you wish to upgrade to a progressive later you decide to do that when loading with the single stage press becomes tedious. After several decades I have not come to the point that I would be be happy with a progressive, although a turret press could be a time saver when loading pistol ammo.
A good balance beam scale and a powder trickler which allows you to carefully approach your target weight are essential, and I also believe that a scale check weight set is as well. When you zero the scale, the farther your sliders move along the beam from zero the greater the potential for error. Again, everyone should have a balance beam scale, but you may wish to upgrade to digital powder measure/scale combination at some time. In the meantime a manual powder measure is certainly useful for ball powder, but it can be less precise and rough to use with extruded powders which tend to be cut off by the rotating drum. Flake powders tend to hang up in it. For extruded and flake powders I prefer the Lee spoon measures. These are quick and easy for rough measurements which are then uniformed on the scale with the trickler.
I don't know if it is possible to buy poor dies anymore, but everyone has their favorites. My favorite dies are RCBS and Redding, and I prefer to have shell holders made by the same manufacturer as the die set. When purchasing straight wall pistol dies make sure you choose carbide so as to avoid having to use case lube. A Lee factory crimp die should be purchased for each pistol die set you own. This die ensures that the case is properly sized and produces a very nice uniform crimp. If you intend to shoot cast bullets in rifle cartridges, the Lee Universal Neck Expander is useful and cheaper for flaring case mouths than is a cartridge specific M die.
You will need a tool to trim case necks because after a couple of firings bottle neck cases lengthen which can result in high pressure situations. The RCBS trimmer is a high quality manual tool that produces uniform results. A chamfer tool must also be purchased to de-burr the inside and outside of trimmed brass. It is also useful to put a chamfer on new brass to make bullet seating easier. A power trimmer, like the excellent Giraud, can be purchased later if you find that trimming becomes a real bottle neck in your procedure.
A linear dial caliper will look after your measuring need for the immediate future. I suggest you get a good stainless steel one rather than one of the cheap plastic examples.
This covers the basics. There are no end of tools you can buy for measuring and case prep from outfits like Sinclair International or K&M. Hope this helps.
Edited to add . . .
I forgot about case lube. Nothing is better than Imperial sizing wax. A little goes a long way. Even so, sooner or later you will get a case stuck in a sizing die, so you might as well purchase a stuck case remover, or make one, right out of the gate. Dipping the case neck in Imperial Dry Neck Lube will prevent the expander button on the decapping stem from dragging without making the powder stick to the inside of the neck.