My advice would be to avoid third party websites that offer free Blogger templates. A lot of the templates are outdated, have little support, and are difficult to customize.
If you don’t fancy any of the free templates available through Blogger, consider spending a bit of money and search for one on Etsy or Creative Market. You should be able to find one that suits you and your budget plus, I have found that most template designers will help you with any problems you might encounter.