Create character style(s) with the font characteristics you want.
Assign keyboard shortcut(s) to those style(s).
Understanding Styles in Microsoft Word

Word is not simple. Sorry.

If you buy a four-wheel drive off-road vehicle and don't learn how to use it, it can kill you or others. If you use Word and don't learn how to use it, it may mangle your words.

If you don't use Word at least two hours a week, you may be better off choosing a simpler product. If you do, you need to learn styles. It will save you time and grief. It really is that simple.