I ended up having to call a locksmith to get me into my apartment which cost $250!

If you go that route, have someone there to remove his belongings for him along with a locksmith to change the locks at the same time. 

It will say how many days you must wait until you legally use a locksmith to enter in your units under emergency.

Do I arrange tow trucks for that date (along with locksmith for house)?

Assuming you have an entry clause...  24 hour notice during normal business hours and I will be there with a locksmith. 

If a tenant locks themselves out, I have a spare to sign out to them or I can go open the door (there's a fee, but it's cheaper than a locksmith).If I sign out one key and it hasn't been returned yet, I still have a second in the office for an emergency.

There is the old story about a driver who locked his keys in the vehicle and had to call a Locksmith to open the door to the vehicle.

If the tenant isn't available to let them in, I need to call a locksmith on top of it. 

@Radley Estrada, and actually, if they lose the key, and they want to drill it out, or hire a locksmith to do that... that is no sweat off of my back, the worse they can do is screw up their mail box.

If they changed the locks, you need to call a locksmith.