The stats on the character sheet are generated as explained in the player's handbook. You don't need physical dice as the internet has many ways to generate those.
>Will you display the situation on a grid somehow in an image so we see what's going on or does everyone have to do that themselves?
There will always be a map where appropriate, I will provide that.
>How much does everybody know about each other? Do we know all other players character sheets with their stats and abilities? Should we design them together or just for ourselves?
You will post your character sheet and keep track of your inventory. I can provide an "inventory sheet" but typically it's just a list. No one knows exactly what's in your inventory but you unless you die and someone loots your body. So you only post that at that time.
If you want to get more complex, there will alse be a character body injury sheet that you would keep but it's optional. I will keep track of that independent of you. Say if your foot is injured, you will travel slower, I will give you that information and correct you on your move commands.
In game, all members of the same party are expected to know each other's backstory and current stats, but they may not know your current status effects unless you or I tell them. For example current HP or MP.
