Check out example codes for "C# check if is first run". It will help you in understanding the concepts better.

Code Example 1

if(Properties.Settings.Default.FirstRun == true)
{ lblGreetings.Text = "Welcome New User";
  //Change the value since the program has run once now
  Properties.Settings.Default.FirstRun = false;
  Properties.Settings.Default.Save(); }
else
{ lblGreetings.Text = "Welcome Back User"; }

Learn ReactJs, React Native from akashmittal.com