Need advice on app comprehension by users

Hey ! I am making an app but so I can make it available in all countries, I need it to be language free, means all has to be done with pictograms or signs. So I’m here to ask you fellow thunkers from the world which are for you the best pictograms in all categories.

-To confirm a username
-To say something has been rejected
-To say something has been accepted
-To navigate to previous
-To navigate to next
-To come back to menu
-To make an action again

Thanks for helping !

it´s impossible to anwser this question because each app have their own context, and depend of that context, you need to put one theme or another, i recommend you two things:

2.- Use simple and reconized icon, like arrow to go back and foward, but i repeat depend of the kind of app and the theme than you like to give to it.