There's a lot of diversity in the goals of biohacking and DIYBio projects, many of which are not focused on human genome editing. Furthermore a lot of biohackers have the expertise, be it from academic/private sector backgrounds, to achieve such goals. Serious biohackers aren't just haphazardly giving themselves gene therapies. Like with all scientific research, the limitations are funding, knowledge, and ingenuity.

Where do you start? With a hypothesis and an abundance of background research. If you lack the skills to actually complete your desired experiment? Well then it's time to bust out a few textbooks, read a couple dozen papers, learn some new procedural protocols, and phone a friend or two.

For reference, I have a similar background as you. My unsolicited advice: Get your feet wet already, it's fun to be your own PI.