Later or then

Later or then
 

At nine I get up then I get dressed.
Can we used later instead of then?
If not when do we use then?

At nine I get up then I get dressed. This suggests that you get dressed immediately after getting up.

At nine I get up, later I get dressed. This suggests that you spend some time in the morning wandering about naked (or dressing gown) before getting dressed.

Perikles' comments are also true for US English: "do X, and then do Y" suggests one event following another immediately, while "do X, and later do Y" suggests one event following another, but probably not immediately.

Can I use next instead of then ?

Yes.

At nine, I get up. Then, I get dressed.
" Next, I get dressed.
" Later, I get dressed.

The first two are synonymous, the second action directly following the first.
Using 'later' doesn't suggest an immediate sequence of events.

I think using next would make you sound a bit foreign though.. (in British English anyway)