i did karate when i was young too
i think reasons are everything, recently i done aikido for 7 months, and it was an amazing experience. i built trust in my body and in others, also it has strong philosophy attached to it, everything is partner work, so get used to people being in you space
, in terms of self defence it does a few years to get comfortable with using the techniques outside the dojo, and if your only doing 1 class a week for me to move up the ranks to black belt it have taken around 10 years, so don't expect anything too early. aikido is pretty physical, the social aspect is quite refreshing also, but if you are looking to defend yourself quickly then try a more aggressive art. all i can say is go to one session in basic sportsware, you shouldn't need any footware. you could even talk to the sensei before or after a session and just talk. so yeah i hope my experience helps