Hey cruiser, sorry to hear about your loss.
I've been a rec boater since I was a little kid, sail and power so I like you all, don't remember 'what it was like' to know 'nothing'.
On your topic, not sure if this is an OB or I/O boat- there are some safety steps with I/Os that OB's dont require.
Other.... You mentioned trailering. This is a whole separate topical arena than 'boating' so I won't touch on that now.
You implied your family is experienced boating passengers, not operators.
Things I've seen and tips along the way.
Always have at least one other person on board competent to operate the boat in the event of an emergency.
Going to have people in the water on toys, or just cruising ? If planning on toys, the operators and passenger/spotter should become thoroughly proficient w/all facets of operation BEFORE putting people, floats, and lines out (as you know, much more complex affair)
Cognizance including the line (and proximity to your prop) bottom structure/depth, other fixed structures, poles, docks, etc, other boat traffic - to name a few.......
Rules of the road, USCG equipment, safe operation, etc will all be covered in any boating class.
Gotchas for newbies- everything about the boat ramp. Its got this mystical aura about it. For one if its crowded, forget it, not worth the stress.
For two, have some sort of system and never deviate.
Our system to be out of the water in under 2 min was my wife dropped me at the dock, and proceeded to move away and idle about while I retrieved vehicle and trailer. When it was our turn I dropped it in the water, put in park and locked the E-brake, she drove it onto trailer, I hooked the bow line, and pulled it out (She still onboard). We proceeded to the out of the way staging/departure area to strap it, stow gear, etc.
First off for newbie, mechanical and electrical operation of the boat. On the trailer with the flush kit attached, you can go through (repeatedly) engine start, stop, blower(s) , lights, bilge pump, trim/tilt, whatever gadgets you have. Until comfortable. Then under the 'hood' the major systems and what they do starting with the all important battery(ies) and what/where the on/off switch for same is, if equipped. Fuel filler, oil tank if equipped, water/fuel separator, etc....
Operating a boat. I find newbies are hesitant on the throttle- when taking off they like to mush along bow high and not simply apply a good deal more throttle to plane out- then back off. This seems to be a 'feel' thing, I guess... Bow high is the worst thing, you cannot see ahead of you, your drawing a ton of water, and its inefficient.
Docking, second only to putting the boat on a trailer, docking is the most terrifying aspect of boating. IDK, you just do it (how to teach that ?) We are on the relatively calm Indian River of E Central FL, you have wind but not current to deal with. Practice on a weekday when nobody is out. Dont even dream about going on a Sunday.....Your local ramp and such will dictate the best practices for docking, IMHO.
I'd also suggest, use the same ramp a bunch of times. You know as a boater they are all different; the pitch, the end of ramp, the dock(s) arrangement, parking, parking lot logistics, water depth, markers, hazards, etc. Dont make this a variable too early, knowing your ramp takes away a lot of stress (A newbie doesnt need).
Be the first one in at the sign of oncoming weather (basically any FL summer afternoon, eh?!) - there will be a 'ramp rush' when the weather deteriorates, dont be part of it. Or better yet, boat in the morning, its almost always calmer (pre shore-breezes) and cooler...
