Why don't I have any friends?
Solution 1:
If you are playing on iOS, you get friends by adding them to your Game Center account - any friends you have there that are also playing Tiny Tower will show up as your Tiny Tower friends, and you can then visit them and gift them things.
To add a friend to Game Center, you need to sign into the Game Center app with your Apple ID, and then there is a button labelled "friends". Tap that, then tap "add friends", and then you can either add friends using their Game Center username, or their email.
You cannot add friends from within the Tiny Tower app itself.