Our Community would be glad to troubleshoot such an issue with you, as this usually means an app is overtaxing the processor. We have lots of happy Moto G6 users in our Community. One thing I’d suggest just from looking at your home screen would be removing the Facebook app to see how the phone performs without it. You can access Facebook through the browser while you test the phone without the app.
If you’d like to troubleshoot further, please post in our #problems category so the Community can try to help.