You are competing with thousands of other breeders who have access to much the same parents as you will start with. Specialize in whatever will make your breeding most distinctive. In large part, breeding is a game of numbers and persistance. Your goals are more likely to be achieved if you spend enough effort on them, rather than haring off on every whim and fad. Optimize your methods to be productive.
Breeding is a long-term effort.
Choose a level of effort you can maintain, and get the most from it. Start with varieties close to your goals. Learn what's known. Chances are that some others have similar goals and can share useful experience. Breeding is a social process.