A good bit of thought with an ASCII table right in front of you should reveal what patterns are in the table itself. Forget explanations, just LOOK.
Be sure to find a simple one, 128 characters arranged as 16 x 16 and numbered in hexadecimal.
If you can’t figure it out from the table, and that includes rejecting ideas that’s there’s some overall organization that just spending more time doing nothing will reveal. What is there should be clear in minutes at most, memorizing key characters should take longer but really it’s pretty damned simple.
If you can’t figure that out then why bother coding? Honestly, I have trouble believing that you ever really looked at an ASCII table, as opposed to skimming to find certain codes.
char zeero = ‘0’; // zeero = 48
for ( byte i = 0; i < 10; i++ )
print( zeero + i );