I dont use them but once you got your Android go and check at Google Play Store. At my Pixel XL you have Allo, dont remember how is written, Hangout. Many people use Whatsapp, again no remember how is written. I only use the stock SMS app that comes with the phone. Some people use Textra, others use Telegram.
You are going to be in another Platform, Google Android Platform . When you use a Google phone it's know as pure Android. When you use a Samsung or LG , just examples, you are using a version of the Google Android Platform, some people call it SKIN. For me, and just me, my favorite is Samsung version of Android. That's the reason I pulled back AT&T Nano SIM Card from my Apixel XL to my Galaxy S6. Some people at the different Android Forums may call me a Samsung Fan Boy, others just a crazy dude that owns a Google Pixel XL but use a Galaxy S6. I am 60 years old, can't be a Fan Boy of anything. I just like the Samsung Galaxy phones, that's all. In the next days as soon the Galaxy S8 Plus, arrives at AT&T I am going to give in trade in the Pixel and the Galaxy S6 and pay cash up front whatever AT&T ask.
So, enjoy your future Android phone, read at the Android Forums and be happy with the Platform you like, and the phone you like.