Have I made a mistake buying this board?

I recently got a fish 5"9 board but I have only started surfing since summer, the issue is that we do not have surf hire except from july onwards where I live so I had to get a board as I enjoyed it a lot. We have fairly consistent surf from 2ft+ (occasional flat days but nonetheless pretty good) so I thought having a fish would work best for me as I have little storage space as well and they work well for small days. I took it out for the first time last week and I found my pop-up technique was hopeless. I was wondering if there was any way I could make such a drastic switch from longboard to shortboard or am I being too optimistic? I am 5"4 and 132pounds and fairly muscular, I do have a lot of upper body strength and do a lot of running, lifting, swimming.