Eventually I wanna make sure to have enough energy to power the air conditioner if necessary ( it's a residential one the previous owner installed in the boat), a fridge (camping one) a microwave and a water boiler.
I would return that monstrosity inverter, and get a 2000W one, absolutely.
Air conditioner is a complete non starter, it is an order of magnitude different from all else. There are 100 threads here on powering an airco, you will need a huge battery and panels. You need numbers on that model, no guessing... But a 2000W inverter will run it at night if not using other stuff.
Don't buy Renogy, certainly not on a boat. Get Victron. I wouldn't put a Renogy in my truck, camping 2 miles from a Walmart with replacements...
I would go 24V system myself. There are some 24v airco for truck cabs I'm looking at videos of, almost all LED lighting can be bought 12 or 14v able, fridges are 12/24v. Only Maxxair or Fantastic fans are 12v or a diesel heater.
However, the other items:
Your fridge is a dc fridge, good. By the way, almost all dc fridges I have looked at can use either 12 or 24v! Certainly most Dometic, ARB, Bouge, Iceco.
A small 700W microwave actually uses 1100W to run, no matter the power setting. Buy an INVERTER microwave instead, they actually use less power when run at 70% instead of just cycling 100% power on and off.
You can run both on a 1500W Pure sine wave inverter, but get the inverter microwave and it can use less power.
Get this $119 Emerson
Emerson MWI1212SS Countertop Microwave Oven with Inverter and Button Control, LED Display 1000W 10 Power Levels, 8 Auto Menus, Glass Turntable and Child Safe Lock, 1.2 Cu. Ft, Stainless Steel
https://www.amazon.com/dp/B0C15FXWP1/
Or this top rated panasonic
Panasonic NN-SN65KW Microwave Oven with Inverter Technology, 1200W, 1.2 cu.ft. Small Genius Sensor One-Touch Cooking, Popcorn Button, Turbo Defrost-NN-SN65KW-(White)
https://a.co/d/iditsZs
Water boiler, get a 120v electric kettle, they are 99.9% efficient converting power to heat. Decent ones are 1400W, again a 1500W inverter will run them. Yes, you waste the 15% of Watts converting dc to ac as inverters are only 85% efficient. However, a 24v electric kettle is so slow and painful with such few and poor choices, I wouldn't wish it on an enemy. I researched the heck out of these. I bought both of these because good reviews, stainless, no rust, no leaks, and double walled insulated. This one is awesome.
COSORI Electric Kettle Stainless...
https://www.amazon.com/dp/B09BQD3YDY?ref=ppx_pop_mob_ap_share
This one also good, smaller but stable base:
BOMICHING Electric Water Kettle,...
https://www.amazon.com/dp/B09YLT13QW?ref=ppx_pop_mob_ap_share