I used a single stage Pacific (Hornady) or RCBS press for almost 40 years. .38 Spcl., .357 magnum, .44 magnum, .223, .308 and .30-06. Then I added 9MM, .40 S&W, .357 SIG, .300 BO and just lately, .380. Too many calibers with too many dies.
I bought one of the Lee presses with the 4 die discs that you can install the dies in and just leave them after you've set them up. No more adustments (other than maybe bullet seating depth - but the resizing dies, case mouth flaring dies (pistols/straight wall cases) and bullet seating die bodies are set, locked down and good to go after that. When I change operation (sizing to case mouth flaring or bullet seating) I just twist the die disc in the press to put the right die over the shell holder (I took the automatic disc rotating parts out of the press). When I want to change calibers I just remove the disc and shell holder and install the correct disc and shell holder. Those Lee presses cost around $115 on sale. The discs that hold the dies cost $8 to $10 depending on where your buy them. The discs work with RCBS, Lee and Redding dies (all I've tried so far).
You need a good/accurate scale. For working up loads - or just loading if the powder you choose doesn't meter consistently - you'd want a nice little powder trickler. You meter a powder charge into the scale pan (set the powder measure to throw a charge less than the desired charge weight), put the pan/powder on the scale, use the trickler to gradually increase the powder charge weight till you get what you want. Very slow/tedious, but it works on the IMR powders that don't meter consistently.
For powders that do meter consistently I've used TAC (accuracy, but at charge weights that weren't 100% functional in my 20" rifles - need to do some more testing - with heavier bullets), BLC2 (one of my two go to loads/powders for .223 - accuracy and reliability), H335 (very consistent charge weights). There are other powders people say meter very consistently but I've not tried those, or not used them enough to have an opinion on charge weight consistency with my powder measure (RCBS uniflow and Lyman 55B). I bought one of the Lee powder measures, tried it out and put it back in the box on the shelf for some time when I'm so bored I've got nothing to do but fiddle with it to see why it doesn't work as well as the others (it was supposed to be better).
If you use the scale/trickler method you'd also want a small powder funnel to insure your powder charge gets in the primed case.
And reloading manuals. They are like car repair manuals. One isn't enough. The second one will have helpful info/tips and data on powders/bullets the first one didn't have. The third one will have even more data on powders and bullets the first two didn't have. Etc., etc., etc. I think up up to around 8 or 9 reloading manuals now. Four very old ones and 5 bought in the last 10 years. I have to say, the Lyman manuals have always been my favorites for the amount of info in them vs. the others.