I’m adding surfing to my families outdoor adventure. I’ve bought four out of five members used boards including myself. Momma won’t surf, she brings the snacks. Don’t know much about anything actually related to surfing so hoping you all can take on a newbie and give me some tips. Had a longboard that I felt didn’t support me well. 9’x21.5x2.5. Today I bought a used Vicking that is 9-3x 22.5x3 but it came With side fins but no center fin. I’m 52 so not looking to do tricks just wanna have fun with my kids. I’ve searched online for suggestions on a fin and can’t find anything. Can you help? Oh yeah, I live in south Florida-Miami so I’m looking at small surf unless I go north which we do frequently.