New garmin Explorer: how do you know satellites are locked in/you are ready to navigate??What arre the three mini icons at the top center of screen--what are they?

New In Reach explorer:  old Etrex told you when it was locked in and ready to navigate--don't see that on Explorer.  How do I know?

What are the four mini-icons at the top center of the screen?  Looks like a pointer (means what)  Box with number of notifications and a cicle with a cross in it ....?

Thanks,  Jim