I am stoked for you Roberto... you are about to start an amazing journey into SUP surfing!!!
Yes, boards and construction have made great advances in recent years, but you can still start out on a low priced used board. There are plenty of good used SUPs that would be great to learn on and help you decide where you want to go with your second SUP.
While there have always been wider boards available for beginners, you generally outgrew them as you progressed.
Some had good shapes but many were heavy.
If you are particularly big or older, or just require more stability than most used board offer... there are new designs that really change the game!
Here is some info if you are interested in new:
I am the Sunova mascot and have actually been totally absorbed into the company after my years of passion for their boards.
I spend much of my time consulting people on board options for beginners or advanced riders.
(Sunova's are available in many locations in Europe... contact me if you need help finding a dealer)
My life got much easier a few years ago when Sunova came out with a number of designs that not only surfed better, but they achieve great performance in larger sizes up to over 35" wide
This gave me a whole new set of options to discuss with beginners or big SUPsters. and people love them!
I finally had a range of boards that even suit my friend who is 6'11 tall. and wanted to learn to SUP surf. (Pic below)
The best news is: these bigger boards surf so well; that you will not outgrow them as you achieve higher levels of performance.
I regularly ride a board that is 34" wide and super stable, but the kicker is..this design has also won on the world tour.
The range goes from 23" wide to over 35" wide and still surfs amazingly well in the bigger sizes.
I am not saying that you need to run out and buy a new board to learn on..
But you could, and you would not have to upgrade for years.... if ever.
I do not like to give info based on words alone, so I add pics and video to help the reader make up their own mind on what they see.. rather than just what they read.
Here's a video I made recently on width and volume that goes against conventional wisdom.
I am so stoked that I now have boards that I can recommend to just about anyone!!
Good luck in your journey!