Here is a link for WSJT which has all the info you should need.I went over to a friends house so he could demo his system for me.
It worked intermittently but I did find it interesting. Where can I learn more about this? I know I studied all of this for my Extra Class license, but the course material did not cover much on the details of equipment and setup. Just band width power levels and the theory behind it all.
Basically you need CAT control so the JT65 or other digital modes software will key your radio automatically, then you need audio in and out to a computer soundcard which transmits and receives digital info from your rig.
You also need to have a time synced software program running on your computer to make sure your computer is running at the precise time. There are links on the WSJT page for free software like Thinkingman which runs automatically in the background. Correct timing is crucial for a lot of digital modes and the internet time isn't absolutely time correct.
https://physics.princeton.edu/pulsar/k1jt/wsjtx.html
Most modern rigs have CAT or C-IV control along with audio in/out so the need for external hardware isn't always necessary.
What radio do you have that you want to use digital modes with?