How to create a font from vector icons (in .ai format)?

Question

Fonts

Hello.
There are .ai files, icons are outlined in them.
How to make fonts out of them?
Also, a question. There are such icons:

Now for these icons on the site a bluish background is added when you hover the mouse. How would it be correct to implement such a change after they are in the fonts? After all, as I understand it, each icon will correspond to a letter.
Or will you have to cut out the icon itself without the circle and add this stroke with css?

Answer 1

There are plenty of programs for creating fonts. There are both opensource and paid ones, everyone can import a vector for characters.

Answer 2

Or will you have to cut out the icon itself without the circle and add this stroke with css?

Optimal.