Help SSL certificate error, site going live tomorrow!

Hi, I had my web hosting company put a positive SSL on my shop website, I didn’t realize that it would have issues with the images and show as unsecured. I changed the url in WP General Settings. I also changed the wp-config and added the define lines. But that didn’t help. So, then they did something in the .htaccess file (accrdoing to this But that didn’t help. So then they told me to put the Fix SSL/Non-SSL Links plugin, but that didn’t help. So they said it could be my cart plugin, I have woocommerce on this site, I selected the box that says… Force secure checkout Force SSL (HTTPS) on the checkout pages (an SSL Certificate is required). But htat didn’t help. So now I think maybe I should just have the SSL on only certain pages, but I don’t know how. They sent me this.

But I don’t know what to follow because there’s two things and I don’t know if it will help either. Any help please? I don’t know how to fix this and the site is supposed to launch tomorrow. I need clear instructions that will work to follow. Can someone walk me through this please? But I need to have it fixed by tomorrow.