Do you have input and target sentence pairs? If so, a logical place to start is to consider a sequence to sequence model like those used for more traditional machine translation tasks. Take a look at this tutorial:
https://pytorch.org/tutorials/intermediate/seq2seq_translation_tutorial.html#sphx-glr-intermediate-seq2seq-translation-tutorial-py 2
This tutorial is well written and should get you going. Btw, your project sounds like an interesting one. Good luck!