I'm having some problem in focusing buttons

I'm having some problem with some button focus effects, although, I don't know if I'm supposed to use focus or not. So yesterday, I was trying to make a coffee roasters website. Now I have to create some options eg. What type of coffee the user wants and how much etc. So for that. I made h1s and below that I made some buttons. If they click on a button, It should change it's appearance so that the user knows it's selected now, when I am clicking on another button from another category, the previous category button is getting deselected because I used focus.I want all my categories to have different options and that the user can select any one option from a particular category but in terms of categories they can select a button from each category without deselecting the previous button from the previous category. I hope I didn't complicate the question but how can I do that? Please help me somebody!