Hi Geeker,
I had a similar experience, but luckily I'm quite familiar with the theme and, for those that aren't, there's always Google.
I think it's safe to say that if you don't have the theme, the crossword will seem pretty impenetrable but, once you get it, everything should fall nicely in to place.
My FOI was 22a and that was followed by 22d, 20a.
The first themed clue I solved was 10a but unfortunately I only got it from the definition and crossers, so it wasn't much help, and it wasn't until I'd solved a couple more that the penny finally dropped.
If you do get stuck you might try 21a, 22a and 25d, which should give you a toe-hold.
Thanks to Paul for a challenging and fun puzzle.
Stay safe:-)