Dogmama said " I didn't realize that there was so much to know"
It's like cycling, it's something you can do your whole life. After over 20 years I'm still learning.
As for choosing a style at the high or advanced end I feel that most styles are more similar than they are different.
Aikido, a "soft" style becomes direct and powerful as you advance, Karate and other "hard styles" have fluid throws, sweeps and other moves.
What's most important is that you find a teacher and school that you feel comfortable with. How do they treat beginners? With patience and respect? Do the advanced students look inspiring.
good luck and keep cycling too!