I was in the same shoes as you about a year ago. I bought a bunch of hand pour stuff second hand and began that way. It was relatively cheaper to begin with as an injector was an added expense at startup. I also found hand pour open style molds are cheaper. Hand pour molds are also available in full round versions.
This is a crazy addictive hobby, but so much fun. I joined a Bass Club and have learned very little from them. They do a lot of talking but tell you nothing in the process to protect their secrets. Here is the exact opposite. Guys are more than willing to help out, troubleshoot problems, share recipes, ideas and tricks they've learned along the way.
To answer your question, either way is a great way to start. If you're good/steady with a hand pour, you can make some phenomenal baits. There are a bunch of guys who do impressive work. If you're like me and not so steady, you'll find injecting much more satisfying. Laminating plates can be purchased to make 2 colour baits easily too. Catching a nice fish on something you made is so satisfying.