For the most part people who do translations know the language or are able to google translate fairly well
I use: my brain, google translate (it's more trustworthy now) and other translator that i find trustworthy.
Which language are translating from? Maybe i can recc you some
I would recommend looking up the manwha with translations of a language you understand, (spanish is a good option if you learned a bit of spanish in school). Sometimes translation apps mess it up. You can also buy the phsysical copy in english and then take the text out of that.
how do you guys translate raws?? there's this manhwa that hasn't been updated and I tried google translate (the app) but it doesn't work （/TДT)/