Hi tenar
Step 1. learn to sail.
Step 2. become familiar with the variety of boats that are out there.
Step 3. buy a boat.
You can shortcut that but I don't recommend it.
Step 1. learn to sail.
This will depend on where you live and how many weekends you can put into it.
55 years ago I got on my bike and rode for a couple of hours to Albert Park lake.
Just did a search and they are still there
albertsc.org.au/index.php/learn-to-sailIf you can learn together competitively it would be great.
Step 2. become familiar with the variety of boats that are out there.As you learn you will see boats around you and be able to talk to other sailors.
everyone has a different favorite. For example Ilenart has suggested steer clear of mirrors because of their rig. I would say go for a mirror because it has such a rig. There you go.
Also you never know when someone will say. "Well I have a ....... that is not being used, You can have it."
Doesn't really matter what it is if it comes along by chance, does it?
Step 3. buy a boat.The secret to this one is wait, if you can.
I love your plan and my suggestions are to help you on your way.
If you can get the kids sailing competatively against kids their own age, you are on your way.
gary