Hey Brandon,
I started my first template roughly 3 weeks? (If i remember correctly) after writing my first line of code Holy crap! It was so confusing. There was a vast amount of code that I didn't understand, I often ran into the same problem as you're having, which I assume is totally normal for a noob. I learned a decent amount from it but more mainly, it instilled me with confidence, I was like damn...a month in and I can make something this decent...where will I be in a year!?
The problem isn't you don't know the template very well, it's that you don't know the basics that well (no one does this early on). I'd suggest finishing a template and then doing what Time Ferriss calls "no stakes learning". That would be a free site, or a project etc. If a company expects a site to be pixel perfect and you're giving it to them for free...well, moving on. You can always update the site in the future when your skills improve. There were times in the past where I stopped working on a template, just studied/practices raw HTML/CSS and came back to the template and just knew how to fix it. Curious, how are you doing? Would like to hear an update and how things went. BTW check out bootstrap studio and other WYSISYG's.
And yes good templates are coded with SEO in mind, something you probably won't do well as a new developer.