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?
Since you are a beginner you'll find the easiest experience with a 3rd party website, such as Coinbase.com, because they handle everything for you. It may be a good idea to start with them just to familiarize yourself with how things work. Use small amounts. They also have a mobile app and their security is good.
As you get more comfortable you can move away from Coinbase (or keep them for only smaller amounts). There are a couple reasons for moving to a wallet you completely control yourself, such as Electrum. First, with Coinbase your identity and coin use is not private. If you will use your money for anything in a legal gray area, such as gambling, your account may be frozen or closed. Second, as people will tell you here, it's always best to control your own coins (the private keys) because that's the only way you're sure you own them. With others you only have an IOU. That's not so bad with a company with Coinbase as they're very large and professional, but you should be careful with others.
For larger amounts use a hardware wallet such as Ledger. Another good option between a 3rd party and running your own software is blockchain.info. With them you generate your own private keys using scripts in your browser. They also have a mobile app. They're a great option to get up and running fast and experiment and learn. However, remember they are not the same as completely controlling your coins yourself, because you're trusting the software they give you. Hope this helps