Hi Wilson!
Welcome to the hobby, and welcome to The Gauge!
To go up 2 feet at 2% (a reasonable grade - you can go to 3%, but you will limit the length of your trains), you have a few options:
1) Helix - a big corkscrew kind of ramp in one corner of your layout room.
2) A "No-lix" where your entire (or most of it) layout is built on a grade around the room.
Anyway, here is the calculation:
Grade = rise/run
2% = 2/100
Since you want to go up 2 feet,
2% = 2 feet/ X feet
It is a straightforward calculation here, so your run = 100 feet.
So your helix will have to contain 100 feet of track. If you go the no-lix option, you will have to go steeper, since you do not have 100 feet of run around the walls before you get back to the starting point (10+12+10+12=44 feet).
If you have a plan already, you might want to post it in the
Track Planning forum for some suggestions and advice on how to work in your elevation change.
Andrew