There are two ways to hand in work. You can either click 'Turn In' on the work (if there is a button) or go back to the Assignment details and click 'Hand In'
This is the easiest way to upload photos for assignments. But it does need a device with the Google Classroom App installed.
Read and Write is a really useful tool for reading and writing while on the computer. It can read work and can turn speech into text.
You may have seen it appear on your toolbars as a little purple jigsaw piece. If you have not you can get it here