I feel like the process of creating your own blog/portfolio website is much simpler than people tend to believe. In most cases it is as simple as finding a css styling format that you appreciate and then, with a basic understanding of both html and css, modifying the specific attributes that you would like to look different.
Because of how readily available resources and information on both languages are, I feel like the learning curve for adapting templates is truly not that steep.
Not only is website building good for growing your understanding of html/css, it is also a valuable asset to point possible employers to when attempting to sell yourself. Mainly because a website is a much clearer/cleaner interface than a github account where someone may have to dig through loads of random projects to find something with substance Now at no point am I endorsing using a template and then trying to claim it as your own work. If you use open source html/css by all means credit the origin. In the end if you do attempt to misrepresent someone else's work as your own, it will most likely come back to bite you.
The reality is regardless of whatever changes you made to the asthetic, the foundation is still the same and someone else is responsible for that work.
Setting that aside, there are still many things that you can do to represent your past/active work through your website, even if your website is not an example itself. Take projects that you have created and extrapolate some of the imagery, whether it be within the program itself or the readme.