Start with what gets you most jazzed in your life. Find another person who enjoys the same thing. Engage in that activity with this "friend" and see if you are both drawn towards the idea of dating.
Keep sex out of the game until you are sure you want to give this relationship a long-term shot. Sex clouds everything. Sex blinds us to the red flags that could be burning right before our eyes. When the sex hormones kick in we are no longer capable of making rational decisions.
Don't let any of your shit fester and darken your experience of life. Life is too short to be compromising with someone you don't love 100%. Oh, and it's your responsibility to love them at 100%. It is your intention and actions, for the rest of your life, that will determine the success of your next relationship.
Parenting is a life journey that I've committed myself to. My partner should have the same orientation. And tennis, being my favorite sport, is a passion that if shared, can unlock a lot of positive feelings and shared time together.