How do you sharpen a blade

without using a knife sharpener of any type

or make another blade dull

'I use it for protection*
not for cutting

just to let you know
& it comes in handy sometimes

If you're using it for protection, let me tell you now that an attacker can easily use your knife against you- your best weapon is your wits and your hands.

If you're worried about being attacked, take a self defense class- in them, you learn techniques to get away from an attacker wit a weapon, or someone who has grabbed you from a number of different grips and positions. Take a look at your local community centre and see if one is coming up soon.

you let your dad do it

You can sharpen a blade by using another one. You screech them off each other at the sharp part, and they can become less dull that way.