hi jacobasmith, if you are just getting in to the sport the easiest thing to do is buy a cheap garden shed and alter it to house your birds in.....you dont really want tp go to a lot of expense as you may decide you are not cut out for keeping pigeons so therefor you wont waste a lot of money.
if you are starting with a few young birds you will need some box perches, a water drinker, a feeding tray and maybe some pots for grit/minerals.....
there might come a time when you will need to build another loft if you get to like pigeon keeping, or you can divide the shed into two to house ybs and obs and then you will need nestboxes for them to raise their young......
hope this is of help to you....