Unable to fix banner image size

[Leannedoja]

Hi, I came on here a few days ago to fix my banner size, and I thought it was okay, but after looking closer the desktop image was pixelated. That's probably because I had resized the image using Canva, and then making it bigger made it look bad. So I put the original image back on my page. It's way too big though, and now looks bad on both desktop and mobile. I have tried all of the online solutions I could find, and I just can't get it to look right. Can you please help me get this image resized? Thanks so much!

Update: So I sort of fixed it. Is there a way to move the banner image position down? I resized on Canva again so the image is clear. The very top of my image is cut off, and the background color is visible on the bottom. I just need to move it down so the top part will show, and the background color will not show. If that makes sense.

Thanks again

Website is     https://weekendcowgirlboutique.com/

The website is : https://weekendcowgirlboutique.com/