If you want to build a simple forge then make a side draught forge with a champion blower. Mine is based on an 1/8 in 24in square plate with a 4 in high wall fore and aft and 6-7 in left and right, The air is from the left and I use a heavy freight wagon wheel bearing from an old hub. A 3 inch stove pipe fits right in. The pan is nailed with common nails to a pine table.
The tools that you need to buy to start a forge are few and simple. An anvil, a fire, a blower, a leg vice, a slack tub, coal, a cross pein, and a ball pein- 32 oz and 32 oz. for steel you will need 1 in square or larger for hardies and swages. 1/2 square for making tong jaws, 3/8 round or square for reins. 1'4 round , 1/4 x 1/2, 3/4, 1 and 1/2 x 1 are good starters for steel. Buy 20 foot lengths for best prices. Get a heavy truck coil spring for punches etc, A few chisels, a centre punch, files and a box of borax will round up your tool kit. When thst is no longer enough get a post drill and a swage block and a copy of bealer's book Practical Blacksmithing.
Anything that can be done quicker with a welder can be done cheaper with a forge and you will learn something of value. If you want a photo of my 200 dollar set up, let me know.