I would keep the length as it is but tidy the upper lip a little, any longer and it will begin to look scruffy. On the other hand, a beard that is too carefully trimmed, and shaped, with super sharp edges, especially with the neck clean shaven right up to the jawline, frankly makes my skin crawl. I think it is an appalling look for a man, but it is your beard so do what you want
You should trim it to define the edges and make it look well-groomed. However, as Richard says, you don't really want the edges to look unnaturally sharp, as if the beard was painted on.
It's good to trim generally about the neck crease. For the cheeks, don't define a sharp line. Just trim off the stragglers. Leave a little variation in the cheek lines, this looks more natural.
I would do the neck for sure. That could be a clean line or a "fade" depending on the tools you have. You wouldn't have to go all the way to the jawline. To the gentlemens' points above, I think with your length it won't look like a hard line anyway unless you went at the edge with a scissors at a 90 degree angle.
I usually suggest cutting a line at the top of the cheeks but your growth is very even there so you could avoid it if you want.
It also looks like one side of your face grows faster than the other (perfectly normal) which makes the chin look uneven. You might want to trim just enough to even that up without losing much length. If you haven't done this before, look up point cutting and layering techniques to make it look natural. Or have a barber do it. This would be my approach to the mustache too, if you trim that, although from the photo it looks fine.
Needs a nice trim. Definitely some defining with a trimming around the jaw line. Nice color by the way. Looks curly, so I'd either keep it close cropped or go for the ZZ Top look.
And some cheap sunglasses thrown in and you'll be knocking people out!
Welcome. Personally, I like my beard kept trim. I also keep my neck clean shaven. I have grown it out around Christmas, but the neck is still shaved so it looks trim.
I had a beard for a lot of years. If you don't trim it, you look scruffy.
ZZ Top looks scruffy
Dr. Strange looks classy
Don Johnson on Miami Vice looks scruffy.
It has to look like its supposed to look like that. A hint, if the beard isn't filling in at a spot, it's going to look much better if you mostly clear it out with clean lines and have a nice solid beard.