Actually I didn't try to do things that were suggested, like sending all dhips from one planet to a point, or making fleets with a starbase, because I because I wasn't sure how those things were done. I have never used a governor because I'm not sure what would happen.
1. A new ship is built and launched from the colony where built. It has 6 moves left. I set its destination as Rally Point 322. It does not move. I think maybe it has to wait till next turn for the rally point destination to take effect so I skip it. Next turn I watch to see if it moves... it does not. I begin moving it manually, 6 moves per turn. After several turns of moving the ship manually, I try setting a rally point as destination...doesn't work, so I continue moving the ship manually.
2. Another new ship is built and launched from colony. I set destination as Rally Point 87. The ship takes off immediately and moves 6 moves each turn till it gets to Rally Point 87.
3. I gather 3 ships together to form a fleet. I set destination as a rally point. The fleet does not move. I move it manually for a few turns, then try setting a another rally point destination...still does not move except manually.
4. I gather 2 ships together and form a fleet. I set a rally point destination for the fleet. It moves automatically to the rally point.
After posting the above, I thought of a possibilexplanation. Could it be that the destination has to be within the range of the ship from the starting point, notwithstanding that you have colonies and starbases all along the route so the ship's range is never exceeded when you move it manually?
Thank you for your replies. They are much appreciated.
Dark Avatar does not seem to have commands for "Go to Colony X" like other similar games do. This command is useful because you don't have to set up rally points. More importantly, it means that your ships ar continually landing at and orbiting colonies and adding to their protection while they are waiting for whatever you are going to do with them next. Ships at rally points aren't protecting colonies.