Posting Images

I haven't updated my webpages since Covid.  Now I have to edit my pages on the Homestead website and not from my computer.  I'm trying to post images and I do not want to post the thumbnails on my page.  I want to post the picture itself and avoid the clicking on the thumbnail to get the full picture.  When I post the thumbnail it is only the square thumbnail and it just shows the square thumbnail itself.  On the old Homestead on my computer, I could post the picture the size I wanted on the page and now I cannot.  I tried to download the new Homestead Sitebuilder on my computer but I get the 404 message that the page isn't available.  Can someone help me figure out how to do what I want to do.  It was soooo easy when I could work on the pages on my computer and then upload them.  HELP!