Well, there is the official save/load tutorial:
I'd suggest giving it a go, fiddle around with it a little, there's nothing wrong with making mistakes, it may help you a lot more than someone just giving you the code, but of course if you have any doubts just post it here and I'll totally help you out.
Also, if you're familiar with JSONs from maybe other sources, I'd deeply recommend using them here. They are amazing for storing data and are my go-to data model when dealing with multiple saves. If you are not familiar with them, just let them go for now and comeback for them later, it could hinder your development right now because it's something new to learn, but in the long run they become very useful.