Not made backing tracks before?
Unless you want your backing track in a different key, tempo or length to the original, then the best starting point is the original track. (This assumes you have multitrack recording facilities).
Record the original track, leaving a few seconds of blank ahead of it to allow for the count-in. To do the count, tapping on the mic head with a pencil will do. Recording the count-in can be a bit tricky (depending on the tune) but you'll get there with a bit of trial and error.
Then play along with the track using guitar, bass, etc. If you have no drums, then keyboards often have drum sounds lurking in them. Record all the percussion items on separate tracks. If you have no keyboard or drums, then cardboard boxes and tin lids are a cheap substitute.
When it comes to the mix, use everything except the original track.