You can download the camscanner app. (search in Google for camscanner either for Android or ios depending on which type of device you are using). It's great for turning pictures into pdf files and very useful for you too. Here are some other tools you can use.
1. To merge or split pdf files https://www.pdfbuddy.com/split
2. To edit pdf files including blanking out info https://www.pdfescape.com/?noredirect=true
3. To convert multiple picture files into one pdf file. http://jpg2pdf.com/
Please make sure that the file is in one pdf for one paper. Your child's name and your signature erased (to protect your privacy) and school name and preparing teacher's name (on last page of papers) removed to protect school's privacy.
If you need help, leave a comment on this thread.