If you have been able to download Photoshop at home then you might be feeling a little bit lost without your teacher at hand! I will hopefully be doing some videos soon to help you - reminders of the basics and some easy and useful image editing techniques. There are some resources to help you below for now - these tutorials re written for the old photoshop though, so you might need to google where the odd tool has moved to in CC...sorry!
There are lots of free tutorials at Phlearn (click on image) - be warned though, they are not all aimed at beginners and may be quite complicated or assume you know lots more than just the basics!
how to make repeated patterns...
This a tutorial for the digital doodle technique lots of you will have done in your Y10 Portraits/Selfie project...
how to shrink people or make them giants!
how to look like you're flying!
how to look like a part of you is missing!
and finally...if you really can't find anything here that you want to do, why not go to phlearn and see if there is anything useful there!
The slides below have 4 or 5 different techniques for basic editing that you could try like adding text, making it look old and so on. It is good because they all use the same image so you can how how different it looks with each technique.