blaking

Since I'm doing a research paper now and i'm not sure if I accidentally plagiarize the contents when i try to paraphrase in my own words, so does anyone know any safe website that has a tool for me to check my essay

For this sentence, What are the sources that prevent solving the issue? do i need the "in" between prevent and solving

Can someone help me to fix this sentence? When I went to get cereal and coffee bag, I did not have difficult time reaching them and putting them into my pouch because they were placed at my eyesight level and not heavy to transfer.

Ia this sentence correct? I had to stay in a squat position while I tried to read the product information because the dry dog food bags were located at the same height as my waist.