Paraphrasing is very simple: it is basically putting what you read in your own words, and in a scholarly context, properly attributing the original author, etc.
Even though English might not be your first language, rather than using a paraphrasing site, for a non-native English writer, I would suggest that you simply follow this basic rule:
- Get a very good translator (or translation program)
- translate the original into your own native language
- after reading in your own language, put the passage in your own words (pretend that you are telling someone about what you just read in your own words)
- have your translator (or your program) translate that in English. Does it make sense?
Perhaps just running what you wrote in English by a native English speaker for clarity will suffice. I work with non-native writers; if you need help, I will be glad to help.