Here's some constructive criticism from me.
Art wise, your stuff is nice! It sort of reminds me of attack of titan for some reason but I like it and gives some nice atmosphere to the comic. Obviously I'm sure it will improve with time, so I won't say much - I think you've got a good idea of perspective and body structure.
For the SFX, I know it's common in other webcomics and might be a personal preference but try to look up different sound effects to use in scenes.
Example: OPEN" The reader should know the door had been open from the panel itself so I would do a "creeek" or "ker-chack" instead.
You mentioned that English is your second language, so I would go over your scripts and text with an online grammar/spelling editor online so you can fix it before uploading it. It might be an extra step but will help to emerge readers into your story!