Can we have an instruction booklet please?

Hi I’ve been on here about an hour, I’ve managed to log in and change password and user name and read some of the posts. But I don’ know about anything else, what do all this codes mean, how do I get a picture off a site for an avatar, what site, what are all the numbers for, I don’t know about a lot of the computer speak, maybe I can wait for my kids to help me. I think it would be very helpful for an instruction booklet with easy language so we can learn about all the computer speak. I’m not being critical just asking for help. Thanks Maz