I would like to know if there are any tools, those that show player information during the tournament, if there are any free tools to use
I believe you are referring to the poker HUD ("head-up display"), which shows the opponent's stats.
As we play against the 'villains' this information is collected and stored in a database.
We can also use them to study our moves later...
...but when it comes to the information they give us, they are very important because it shows the opponent's tendencies.
Some of them:
hand2note
Holdem manager 3
poker tracker 4
DriverHud
I find these HUDs readings so complex, is it just me who thinks that?
Actually about the reading itself, there isn't much to delve into.
You need to know the basic statuses and what they represent.
VPIP - PFR - 3BET - ATS are the basic ones, but they already carry a lot of information.
Some other statistics need more sampling to be better interpreted, other than that, with the basics we already have a great help.
For me the biggest difficulty is in the configuration because despite having several pre-assembled configurations, we must adjust it according to our needs.