There are many websites at which you can learn the "rules of the road".
Regardless of these it is always a requirement to maintain safety at all times. I have been sailing for more than thirty years and if I was in such a poistion I would go astern of the other boat so long as it was safe to to so or simply slow down and allow him to clear.
when the power-driven vessel is towing another boat and has difficulty maneuvering
Assuming you are referring to a fog horn or a warning signal, generally find where the other vessel is and change course accordingly
the vessel operator
Be alert and observant.Scan 360 degrees and act accordingly. ALWAYS look before you leap.
Starboard ( right side ) and it should be mounted so it is visible at 135 degrees .
When a sailing vessel operator approaches a power-driven craft head-on, they should adhere to the "Rule of the Road," which typically requires each vessel to alter its course to starboard to avoid a collision. The sailing vessel should maintain a steady course while keeping a close watch on the power craft's movements. If necessary, the operator should be prepared to take additional evasive actions to ensure safety. Communication signals may also be used to indicate intentions, if appropriate.
The power-driven vessel should change course and speed.
Steer into the wind.
Keep clear... The power driven vessel should, if possible, maintain course and speed. The only rule for overtaking is that you keep your distance while overtaking
A sailing vessel operator when approaching a pwc head on should slow down and change course.
the vessel operator
When approaching a sailing vessel head on, it is up to the motorboat to yield. The motorboat operator should swing wide as early as possible to stay well clear of the sailing vessel.