There is a lot of information to find about the Arduino.
The Arduino is popular because there is a big community very well suited for beginners. The Arduino is made to make it simple to start programming and connect sensors and other electronics.
There are many hardware boards that fall under the Arduino family, so whatever you need there is always one suited for your situation.
Electronics sellers like Adafruit and sparkfun also have a lot of information about arduino (alike) projects, their documentation is mostly topnotch so I won’t document their sensors here.