For let me ins I sometimes wrap a towel around a veranda post, or off hotel door knobs, try it and see how you go. I have done let me ups off a hotel dinner table or go to the hardware store and buy a bit of 1.5" timber dowl, or broome stick and put between two chairs, filing cabinets or as in ML book stereo speakers or buy a door pull up bar and mount it low enough to do let me ups and latter at the right height for pull ups. I have got a set of gym rings at home and use these for let me ups, dips etc, great bit of kit for YAYOG workouts.
Or just start on the legs, you can also sub in other exercise's in place of those two, maybe towel curls in place of let me ins
"Times fun when you are having Flies" Kermit the frog