Then your research is a great start.
If you plan your boat with high power electrical items, (e.g. - washing machine, freezer, refrigerator) - then you'll need considerable power production, storage and handling systems (generation/batteries/inverter) - It can certainly be done, of course, but it costs.
As you scope together the plan for your boat, list the components that you must have (including lights, water pump, bilge pump) and then items that you would prefer to have (e.g. radio, TV, phone charger etc) and then items you would like to have, (maybe) ('fridge, etc).
work out what the probable power consumption will be for those things per week, and then start to consider the different options there are for supplying gthe power.
It'll give quite an insight into how you need to plan your boat.