Tefillin rules

I’m on my religious Journey. Did a Masa program last summer and spent the full summer in Tel Aviv, a lot of it volunteering. Now I am upholding my religious Mitzvahs. What are the rules of putting on Tefillin in an apartment. By rules I mean, aren’t you not supposed to put it on in a room that has a trashcan? That might be a false rule. I don’t know. Looking for insight. Also does anyone have recommendations on Kosher replacement covers for my Tefillin.