Hi
I am at home right now or I am in the home or something else?
You say: I’m at home right now, sitting in my room, watching TV.
basically, in, at, on can be prepositions of location or time. the site below will explain them when used for location.
the rules for time are pretty simple with few exceptions: in a year, month, eg in 1995, in September; on a day eg on Monday, on Christmas, on weekends; at a time eg at 9am, at lunch time. i hope this helps you.
owl.english.purdue.edu/handouts/esl/eslprep2.html