Some places like Target sell them. Your best bet is to go to Ulta or Sephora. I got a bunch at Sephora (and previously at the Body Shop). They're easy to fill and have about 50 sprays before you need to refill it.
Sephora
You can probably find that a gang store like Wally World or Target. Just go go the travel sized stuff.
I have seen stuff like that at Target!
What about testers? They often give them away in stores, and they are really tiny. Enough for 2-3 uses. If not, you may consider getting atomizers. They are just tiny spray bottles, but you can put whatever perfume you want in them, and refill as needed.
buy a travalo.sephora, drugstores, ulta, sears sell them i believe try there :)
Kohl's has so many selections in tons of different sizes.