Hi,
I'm still learning too so might not be able to give you much advice but what I found useful was to download https://responsively.app/ onto my desktop, as it allows to you see your site on lots of different screen sizes all at the same time. I use it alongside Chrome dev tools, as I don't always find the dev tools reliable.
To set the sizes for tablets I placed my smaller css into media queries like this @media screen and (max-width: 83.4rem) {
}
and for phone sizes I placed the even smaller css into @media screen and (max-width: 42.8rem) {
}
0
