I highly suggest you join the IBC (
www.ibcbettas.org). The IBC holds the current show standards for all bettas and its members have a wealth of knowledge that is extremely useful for a new breeder. You may even be able to find a breeder or IBC sanctioned show near you and be able to pick up some very nice stock for very cheap.
I would avoid breeding colors involving Red for your first time (including orange and yellow) as they can be hard to work with. Multicolors are probably the easiest to work with color-wise because you will get a variety of colors. IMO a new breeder should breed for form and finnage before deciding to settle on one color but if you do your research there's no reason why you can breed for form and color at the same time.
I'll third the suggestion that you get a sib pair for your first spawn. It will give you a better guess at what kind of fry you'll get, even more-so if you are able to ask the breeder at little about the genetic backgrounds of the fish.
For fin types I would stay away from rosetails because they tend to produce a lot of bad genetics. Crowntails also because it is extremely hard to produce quality CT unless you have amazing water quality. Halfmoons and HMPK are the trendsetters right now so I would choose between those two. I would also avoid Double tails starting out because you have a lot of culling when it comes to DT because of short spines and deformed swimbladders.
For the spawning tank I'd advise going bare bottom. Many people breed in fully planted tanks with substrates but I prefer a bare bottom tank with non-rooted or floating plants for easiest clean up.