Choosing from two important

Two days ago, my dad proposed a public speaking school.idea which have actually been looking forward to.
But the problem is the timing is very tight. Like why would he bring us an idea I had always waiting for in this critical time in work place.

We are just few staffs and still needs more staffs to be employed.
How do I even tell my boss at this point that I want to resign, what happened to my position, who would take over from me.

This has been my thoughts for the past days and I don't even know where to start from.

Please I will to hear your suggestions in the comments section. If you were in my shoe what will you do?
I really needed this public speaking school before going for service.