The rabbit hole goes very very far...
Just take whatever path suits you.
Some of us are crazy and eventually get full race cars and take them to a track every weekend and others just do the occasional DE day as a break from work/life/etc.
If your preference is in the latter camp, just work your way through DE's and get lots of instruction in car and maybe in a few years work your way up to giving back and instructing others. Some of the best instructors are neither wheel-to-wheel racers nor the fastest on track.
Take it as far as you are willing to go that makes you happy with what you're doing. It is definitely a slippery slope though! Enjoy!