Where to start?
First, Lyman Handbooks offer excellent step-by-step and trouble-shooting information. If you can find a copy of the NRA publication "Cast Bullets" by Col. E.H. Harrison you will have an excellent reference source.
Second, safety is the first and last concern. Always outdoors or in an area with good ventilation and air flow. Eye protection (I prefer a face shield like industrial workers use), heavy gloves (think welding use), no nylon or synthetic clothing (only cotton or wool, which won't melt to the skin). No possible sources of moisture in the working area (water introduced to molten lead creates an explosion as it vaporized into steam). NO DISTRACTIONS! No children, no pets, nothing going on but the business at hand.
I have always used Lee aluminum molds with complete satisfaction. Inexpensive and easy to use with a little practice. Several of my Lee molds are over 40 years old and still performing.
I have two 10-lb. Lee bottom-pour pots. This allows me to work with one while the other is coming to temp, then recharge that one and work the other pot while the first is coming up to temp.
Lots of sources for bullet metal, but becoming harder to find in many areas. The old automobile wheel weights were great, but the new versions are unusable (wrong metals). Old plumbing lead pipe is history. Typesetting metal is history. Range salvage is still possible, but a lot of work (smelting, cleaning, fluxing, etc). Today I would probably order alloys from reputable suppliers for the intended uses.
My preference for revolvers has always been semi-wadcutter style. For semi-auto pistol I prefer truncated cone flat point. In rifle calibers I lean toward round-nose flat points. I have a few hollow-point molds, but the added time in the casting process is significant (and the differences in performance are minimal in most applications).
With the two Lee Production Pots and two or three molds I can regularly turn out a couple thousand bullets in a morning or afternoon session. Fill one mold, set it aside to harden, fill another mold, set it aside, cut sprues, drop new bullets on a padded surface, refill molds. Work until one pot is about 80% empty, then refill with ingots and start on the other pot while the first gets up to temp, stirred, skimmed, fluxed as needed.
Started out with the old Lee lube & size kits, shallow pans for melting the lube, cookie-cutter style tool for removing the bullets from the lube pan. Quickly learned that sizing was not much of an issue for most applications. Picked up a RCBS bench-mount lubricator-sizer press years ago and never looked back.
Fifty years now, and every time I add a new caliber the first thing I do is order dies and bullet molds.
Lots of reference sources available, plenty to read and learn from, many mistakes are easily avoided with a little bit of experience from others.