I had maybe 80 lbs of lead stashed prolly 4-5 years before I started casting. Of course, I started sometime in 1968 or 1969.
My Dad got most of it since he was all over the place and asked guys at gas stations, etc. He had a buddy that had a tire shop, so that helped.
Get some lead first, then start looking for a good pot. In the mean time you can shop for a mold. I have always used iron molds. I tried aluminum one time and didn't care for it, but that is just me. I never tried brass molds.
After that and some read time, practice a lot and you will be in the business before you know what happened.
The very first mold that I bought was a RCBS mold for 357 bullets. Next came the 44 then the 45. Added a few more over the years and I cast for everything I have except the 22 LR. The smallest is 22 for my Hornet and the largest is a 500 grainer that I use in the 460 when I have the urge.
I also do 0.690 round balls to use in the 12 ga.
However you start out, you will have fun and some frustrations. Hopefully those will be minor.