How to tighten crankset

Hi,

I noticed my crankset has some play, but I can’t find much info on this specific model. All the videos I’ve seen show cranksets with bolts in different places. On mine, there’s only one bolt on the non-drive side.

It seems pretty straightforward to just tighten that bolt, but I don’t want to mess anything up or cause damage. I’m also wondering if a loose crankset usually points to another issue, or if it’s better to take it to a bike shop to have it checked.

(I know the bike is dirty. I didn’t want to wash it yet because of the play in the crankset.)

Thanks!