Awesome! Thank you for this forum! I am having trouble with the Lasso tool and how to copy/paste

I have a photo that I’m trying to edit. I lasso part that I want to copy/past over something I don’t want. When I first tried this it sorta worked, but I had to paste it over the undesired place about 7-8 times, each time.  Now I can’t do it at all. I can lasso, but it says I can’t copy it because no pixels are selected.  I don’t know how to select pixels in my lassoed section.  😗