Thanks for your kind words.
You likely need to make sure your images aren’t larger than 512kb. There are a few free image programs out there that you can use to reduce the sizes. You’ve uploaded a zip file, so people will only see that image if they download it. To see it in the post, a jpg is best.
As for the Avatar. Go to gravatar and you will see a place in the centre of the site that says “create your own gravatar”. Fill in the email address you want to use this with, create a username and you’ll need a password. Once you have done that, activate your account, then sign in. The first thing they ask is for you to upload an image. Once you do that and save it, that image should be linked to that email address. Hope that helps!