Just bought a super cheap wig for a cosplay, how to properly wash and shape it?

I can attach a photo later for reference if that would be helpful, I'm just not able to right now. I recently bought a $20, all-synthetic wig for a likely one-time cosplay, except i'm having a really hard time shaping it. I washed it with dish soap in a sink, and per my mom's suggestion used some conditioner to try to separate out the strands, but it seems to be unsolvably frizzy, knotted and tangled. This is probably because the wig is curled/wavy, mainly towards the end. I know that real hair with that texture needs a ton of products to properly maintain its shape, but I don't know how much of that applies to this wig since it's plastic and not real hair (and as I have fairly straight hair, I don't have any of those products anyways).

I've never used wigs before, so I was wondering if anyone on here had any tips. The wig is about just past shoulder-length, for reference