(very) novice question of Quartus Prime Lite

Ladies and Gents,

As my nickname suggests, I am very newbie in the field of FPGAs. Ị would like to build some knowledge up.

As a first stem, I found in my drawer a BeMicroSDK board from Altera and Arrow. I downloaded an dinstalled a CentOs distro of linux, installed a Quartus Prime Lite version of development environment.

Yes, I know, the language of FPGAs is VHDL (or Verilog). But I am a newbie. Since I wanna make my life easier, I started with schematics. I could succesfully debounce a button, create a 2Hz clock out of the 50MHz on the board, and a counter is also implemented.

My first question is:

There are some built-in schematic symbols in Quartus. Clicking on the AND gate at the top of the schematic editor, a funny little library is there. Some of them are self-explaining, but not all. Where can I find some description of them? For example: there is a barrel shift, there are 74 series logic, and so on. I need to know, how these symbols work, because the try-modify-tryagain method is boring.

Thanks in advance for any help!