What is the minimal schematic (needed capactiors/resistors) to use FPGA Altera Cyclone 4 EP4CE6E22C8N?
Typically the best way to start with any FPGA design is to find the schematic of a relatively simple commercial development kit, and strip away the various peripherals you don't need. The advantage of this is that somebody has already done a relatively decent job of working out what is required.

You can also start from scratch with the help of various documentation from the FPGA manufacturer. This includes pin-out files, datasheets, and other connection information. In the case of Altera/Intel devices, you can find pin connection guidelines (PCG) here, and package pin-outs here.



The Cyclone IV PCG file gives you lots of information you will need to know about what each pin does, recommended power supply setups, configuration pin requirements (watch out for pull-up resistors on pins like CONF_DONE without which the device won't configure), all in a nice 14-page summary.

After that, make sure you test compile any designs you want to confirm you haven't missed any pin requirements. Do this before  you commit to getting a PCB made. It's very easy to choose the wrong pin for something like a clock input, or memory interface, only to find out it won't compile.