If possible, can you send me such scans, because I have literally no idea how to get better ones. I had to take screenshots and edit it in Canva on a school account, so it's not very surprising.
I can't translate Japanese, I only know Chinese and English.
I wasn't super sure if you used the forums, but I can give some advice as a fellow translator.
1. Getting raw manga files is usually kind of a hassle since screenshotting is very bad for quality. I buy mine from Kobo, but that only works for stuff with official Chinese translations and it is usually worse to do layered translation.
2. Usually the standard for all the messing with the pages is photoshop though not everyone has that so GIMP is a pretty popular free alternative.
3. I mentioned before, but translating from a translation usually leads to error even if unintentionally. It's fine if there's no translation at all, but I would recommend just waiting for someone who can do it from original. If you want to practice your Chinese, manhua groups are always looking for CTLs
As a final word I will say it is pretty bad manners to pick up a series that's already being translated by someone else without at least first asking. We were just a bit away from finishing our own TL so it was quite a shock seeing a chapter update a bit before our own. Usually a series is only considered abandoned after 6mo-1year of no communication, but even then it's nice to ask if the group has a discord linked since things can happen. Competing TLs suck both for readers and for the groups since a lot of work is wasted working concurrently and most readers don't like waiting for a higher quality TL.