if the player walks for more than 2 seconds then he will start running?

How do I check the times that have passed since player did something?

You could always have an instance variable tick up. It would look like an instance variable called "timeSpentWalking" or something, and if the player is currently walking, then add 1 to that instance variable. This will add to the timeSpentWalking variable every tick. If the player is not currently walking (or running I guess), then reset the variable back to 0. Then you can compare the variable to some constant. In your example, if the character is walking for 2 seconds, then you just have to compare to 2 seconds worth of ticks (60ticks/second --> 120 ticks for 2 seconds). It might look like:

If character Platform Is Moving, then Add 1 to timeSpentWalking

If character X Platform Is Moving, then set timeSpentWalking to 0

If character.timeSpentWalking = 120, then [whatever you want running to look like, including a different animation, or a Platform max speed increase, or new moves available, etc.]

You might instead bind the first and second Ifs to whatever button you're using to walk/run, like:

If Keyboard Is pressing Right, then Add 1 to timeSpentWalking

If Keyboard X Is pressing Right, then set timeSpentWalking to 0

Play with something like that to get a better result, like also adding not pressing left e.g. Hope that helps!

Or use Timer behavior.

Player is NOT moving
 .. Player Set Max Speed to 100 
 .. Player Start "run" timer for 2 seconds

Player On "run" Timer 
 .. Player Set Max speed to 200