Hello Domenico. Welcome to the Ardupilot world! I have similar goals as you and have been experimenting over the last few months with the Ardurover version of Ardupilot. I work full time as an engineer but also have a small farm where I grow hay to sell to farmers with cows and horses. I hope to build an autonomous spraying machine to spray weed killer and to perform some of the haying duties (cutting, teddering, raking). (Hey, I can dream, can’t I!)
I have automated a zero-turn mower and am successfully cutting my non-hay fields with it. I am still perfecting several aspects of it and have everything sort of temporarily installed, but working.
I am using a Pixhawk controller and a U-blox C94-M8P RTK GPS system. I have been through several changes to the RTK communication link between the base and rover. Many other items are still evolving as well. I recorded a lot of YouTube videos documenting and demonstrating what I have done, BUT I badly need to record an update. I recorded a two-part overview which gives a lot of information, but it is not up-to-date. I think if you watch them, however, you will get an idea, at least, of what I am doing. The description under the 1st video also gives a full breakdown of my parts AT THAT TIME. Again, a good bit has changed.
I created a playlist of some of my videos here https://www.youtube.com/playlist?list=PLIsYv3gzZOt9N9yZmpI_WYiMaBQ6HazOG. I do not claim to be an expert but I am happy to share what I have done with you and would enjoy hearing what you accomplish as well!
You will find that Ardupilot will probably not do everything you want, but it has a very rich communication protocol called MAVLink, through we should be able to have a co-processor do other functions in concert with Ardupilot.
It’s a whole lot of fun to watch this stuff work!!
I will point you to one other non-Ardupilot software that you may want to look into: AgOpenGPS (https://agopengps.jimdosite.com/). I have looked at that some, but if I understand correctly, it believe the main software runs on a Windows laptop and uses Arduino and other hardware for control. I prefer to keep embedded systems such as an autopilot and other controls on a more normal embedded platform. But, I’m not ruling it out yet. The author, Brian Tischler, has some excellent videos and has developed some very sophisticated software: https://www.youtube.com/user/FarmerBrianTee/videos.
That’s enough of my rambling for now! You will find this forum very helpful, or at least I have. There are some very patient and helpful experts on here!