To clarify I'm making a simple platform fighter (think Smash Bros) and I want to have the character walk and run using the same keys. I decided on making them run if the key is pressed quickly and walk if it's pressed slowly (the keys I'm using are A and D for left and right respectively). And thus we come back to the title question.
BTW I'm super new to this engine/ GDScript so I'd appreciate as much detail as you care to give. Thank you in advance.