Questions about a NIOS-II Tutorial, and how to learn NIOS

For sdram you will need something written for the exact board you are using. The settings in the memory controller block depend on the type and number of ram chips as well as the exact geometry of the traces on the board. You can't pick a random Altera tutorial unless you have the exact board the tutorial was written for. An FPGA dev board that has SDRAM on it will probably come with an example project or tutorial that uses the SDRAM.