The seed need to be stored at 40F for 12 weeks then lightly cover the seed soil temp65-70F & takes 120-365 days to germinate

I stuck some seeds from my tree in a pot about 2 years ago, and the resulting tree is now about 2 feet tall.

It sat out on the covered deck the whole time.

I want to start a tree but don't know how to get started. Do I use 1 or 2 seeds per pot? and how do I maintain a 40 degree temp. can I just put them in the refrigerator?

Jennifer, yes, stratify the seeds by storing them in a damp (not wet) medium in the frig. I often use a damp paper towel inside a plastic bag, but other mediums (sand, vermiculite, peat, etc) can be used. You could even plant them and use the planting medium (covered by a sheet of plastic wrap or enclosed in a large plastic bag) for stratification if you have plenty of room in your refrigerator.

The number of seeds you should put in a pot will depend on the pot and your own personal experience/preference. You just need to consider how much space the plants will need until you transplant them and how the spacing you choose will affect ease of transplanting them. There really is no single right answer and I still change my philosophy on this from time to time.