You don’t HAVE to buy one. You can watch a million reloading videos online, and find 3 sources for reloading data (only trust info from powder/bullet manufacturers) on a single cartridge in 30 seconds. Hodgedon, nosler, sierra, Hornady. They all post some online. You could also make a post and have someone DM you a photo from one of the manuals.All advice above is solid. I would additionally suggest that step 1 would be to buy a reloading manual from any of the big players (RCBS, Hornady, Lee, etc.) and read it front to back. You will likely find it enjoyable...and it's a great resource to keep on your bookshelf once you start loading (even though you can find load data online). Then, start making some decisions on equipment and ask around from folks on places like here for advice/opinions. Have fun!
Or you can spend ~$20 and have a hard copy for yourself.