So many of these start or end with an `x*`, `(x|y)`, `[xy]` or `[^xy]` that I only see two characters I can fill in before I need to start looking at multiple constraints for the same cell and either doing combinatorics or guess-and-check. This might be fine for hard mode, but as someone who considers themselves a regexpert it's not very approachable as a first puzzle IMO. A more gradual introduction to the format wo…
I agree it definitely feels imposing when you first look at it, but stick with it. Look for spaces that have a very small set of possibilities, and then try to map out what neighboring spaces could have for each possibility. If you really feel stuck, take a screenshot and mark it up.