The kit you will need will vary according to your ambition and location. At one extreme, you can potter about on the river with little or no kit; at the other, a trip off shore will require extensive safety kit.
You will need:- The boat, the outboard, the fuel tank, and more than enough fuel for the planned trip.
- Oars or paddles because one day, the outboard will fail.
- An anchor, with a short length of chain and a decent length of rope. Not only is this good for stopping to picnic, but one day the outboard will fail and you will want to avoid drifting while you sort it out.
- Spark plug spanner.
- Pump. The tubes will go down a bit when the boat is put in the cold water, and again if the temperature drops.
- Baler, if there is any danger of waves breaking over the boat, or heavy rain.
- A painter (rope at the bow) for mooring.
- Windproof/warm clothing. It is colder on the water than on land.
- Sun cream. The sun reflects back off the water, increasing your exposure.
- Drinking water.
- Food for energy and morale when you're cold and tired. Ginger nut biscuits are the food of champions.
- Mobile phone.
- Dry bag or similar for car keys, wallet, etc.
After that, you need to accumulate kit at the rate that you develop your skills and your ambitions. For a day poddling on the river or scooting about the bay, the above is enough. For longer expeditions, travelling further afield, and more challenging conditions, the list will grow.