There's lots of Christmas Traditions Threads on here and a 2 yo will be too young to understand lots of the gongs on, but you can start a few lovely traditions with him.
My DC are 12 and 14 but we still have things we do (though they have changed alot over the years)
Christmas Eve Hamper - no, it's not "Oh what do they need more presents for" bah humbugginess.
The Hamper in our house is delivered when we go out for a walk (weirdly enough, when I check the back door )
PJs, a bath bomb, sachet of hot chocolate, a festive mug, an annual, jar of sweets, bath robe, pack of tiny biscuits.
Lots of these things they need/use and you can buy them in sales.
DD has an old IKEA teaset that she puts out (still 
)
When DS was about 3-4 I made an Elf in a bed, sleeping . We walked down to the playhouse in the dark with a candle in a jar to peek.
Candle in jar "Landing Strip" to guide the sleigh
Watching NORAD to see when he gets to the UK.
Going for a Christmas Eve walk to feed reindeer (or geese, we weren't fussy )
Looking at the neighbours lights and trees one night ( especially if you have a crisp, dry, cold night, pop his PJs under his clothes, wrap him warm , maybe in a buggy , and have a late evening walk, he should be fast asleep when you get back )