1) I have a gallery , by default I am not able to see the first row, I have to click "+" to see first row. How can I make it visisble on the load of the page ?

I have to click "+" for this to appear

2) The code in my Save &Close button is
Once I click , the values are stored in a string and sent to another screen,
Set(AllPrincipalString,Concat(Gallery1.AllItems,Concatenate(TextInput1.Text,"; ",TextInput2.Text,"; ",TextInput3.Text,"; ",TextInput4.Text,"; ",TextInput5.Text,"; ",TextInput6.Text,"; ",TextInput7.Text,"; ",TextInput8.Text,"; ",TextInput9.Text," | ")));
Notify("Principal Added successfully!",NotificationType.Success);
Navigate(Screen1,ScreenTransition.Cover);
But I want the user to user to prevent from submitting if my TextInput1.Text, is empty how can i do that ?