I wouldn't say it's "wrong" loading normalize.css and then loading a reset.css. It just isn't very efficient or helpful. What's going to happen is the browser is going to load all the styles from normalize.css and then remove all the styles from normalize.css after loading the reset.css. So the reset in other words is just going to "remove" any styles that normalize and browser had in the first place. So at that point it would be better to just use the reset.css and not use normalize.css. That is one less file for the user to download and will make inspecting the site using developer tools less confusing.
The reset brings everything to 0 and then you must build up every single style.
Normalize.css instead makes the default styles that come with web browsers look the same. The reasoning behind that is the browser default styles typically are helpful and as you are working you can be rest assured that if you forget to set a size for the <h1>
for example the <h1>
will inherit the default style and render larger than other headings.