Thanks for all the info everyone. Much appreciated.
A bit about me - Im not a web developer/designer by trade - this is just a hobby - but I am willing to learn. I have signed up for (and started) a Udemy course.
Re: The Website - Interestingly, I found another, similar copy of the site I used as my starting template that has a lot less stuff done to it (https://startbootstrap.com/template-overviews/stylish-portfolio/) so I'm going to modify that one slightly and see if I get the same issues (hopefully not).
Again - thanks for the help thus far. I'm sure I'll be asking more questions soon!