The TI-84+CSE is not compatible with programs from earlier models, unfortunately. however, there are plenty of new programs that have come out for the new calculator. TiCalc.org happens to be the best place to get these programs, with the archives being quite big.
link here: http://waa.ai/pfA
no, for some of the programs, you will need the "DoorsCSE8" shell, so make sure you get that app first.