I think you may have tapped all the bubbles to get items each time when you are at a PokeStop. However, it is unnecessary. You can take a shortcut to put items into your bag at once.
1. Tap close button
Now you see bubbles with useful items. To get them, you do not have to tap them all, if you want to save time. What you should do instead is just tapping 'close' icon. Items are automatically transferred to your bag.
2. See which items you get
Obtained items are indicated at the right top of the screen. Unless your bag is full, you got them all safely.
Many thing you should know about PokeStops
The PokeStop is one of the important element of Pokemon Go. However, there are not enough tutorial. See the link below about the details of PokeStops.
