Html errors

[jennland]

I hope I am posting in the right area. I am a newbie as you probably have already picked up. My suspect my problem may be in my gum theme but I don't know that for sure.  I posted here because I saw no specific gum theme folder. Today I used the "Nu Html Checker" tool to check for errors if any on my website. I thought my site would be not bad! But apparently that is not the case. The html checker says I have 21 errors just on my main page. I did not check the other pages.  I am here hoping to find some help with these errors but I don't know how to proceed. I don't think loading a bunch of screen shots on here is the process. Is it possible for someone on this site to input my website https://lazywaytosell.com/ into this Nu Html Checker found at https://validator.w3.org/nu/ ?  This would show you what I have seen. Then if you think you can guide, advise or help in any way? I would be of course very grateful and I would attempt to follow any advice you may have. Thank You
Robert