I read the beginner FAQ, but i am so confused on many points.
I wanna be able to receive bitcoins, i'm not sure if it would be safest to get my own wallet with an app, or use a trusted 3rd party website?
It would be preferably if it could be accessed via phone via an app or so.
Would really appreciate help! Mainly gonna be receiving bitcoins and using it for shopping.
Thanks in advance!

There many trusted and legit wallet for your smartphone or even your desktop. It depends on which country. For example me, I have coins.ph where I keep most of my coins. Also myetherwaller, you can easily use to and is accessible as long as you have a device.