Assuming you are in the factory state, try this:
Set the BSP to internal sync using the sync button (default setting when you switch it on).
Set the TR8 to external sync (refer to it's manual for details on that).
Set the TR8 to MIDI channel 10. I have a feeling it's default is Ch10 anyway, so just check if it's not by selecting the drum sequencer on the BSP and playing some pads to listen to if the TR8 makes a sound. If so they are both on the same MIDI channel.
Now write a drum part and hit play. There is a good chance the TR8 will start it's sequencer too and play whatever pattern it's currently on. You can either clear a pattern and use just the BSP to play the TR8 or use both sequencers to run the TR8. Using both you get the functionality of both sequencers, such as their unique random functions; I'd say it's a good bet that they work differently to each other and it could be fun to run them both at once.
Anyway there's a start. Do a simple internet search for "MIDI basics" to get some more info on running MIDI instruments and then expand how you run the two together. You may find after a little time you'd prefer the TR8 to be the master, getting the basics under your belt now will make that easy when the time comes.
Have some fun!
