Surfing Waves

Hey guys, newbie here trying to get some advice on what I should do to replace my glass on fin. I'm not too versed in surf equipment terminology so please bear with the rough descriptions: I have a 6'6" fish and it has 4 glassed on fins (two large ones and two shorter baby ones sort of adjacent and on the inside of the big ones) and a place for a removable center fin (the screw is stripped....my husband lets me use his knubster fin since it only uses one screw). Not sure what happened to the fin but it just ejected itself from the board and disappeared.

My question is, since I now have to do a fin repair, should I keep all of the glassed on fins? I see from another thread the process of removing glassed on fins. Should I remove the two short baby fins and just make it a normal tri-fin? I don't surf very big waves and I'm still learning, mostly just enjoy cruising 2-4 foot waves and sometimes I feel like the board is a little wobbly. I can only find glass on fins in packs of two and since I completely lost the other fin it looks like I'm going to have to replace both, so wondering if I should just do a complete fin overhaul?

Hi and welcome, I'm a little unsure of the logic here?
One fin is broken off, you can only buy two fins as a pair ( are they the same size as the broken fin ) if so you only need to replace the missing fin.
IF that worries you and you are not happy with the fins ( the board feeling wobbly) take your board to a surf repair shop and plugs fitted for a fin system and you can change your fins to your hearts content.
It may also be is that fish boards are designed to be be wobbly to give skatey type performance in mushy situations