I'm having trouble with calculating IRR. I've been practicing problems to study for my test, but I can't seem to understand it. When you're given an initial cost, expected net cash inflows for x amount of years, and a cost of capital what is the best way to solve for IRR? I've tried manually and through Excel. When I try using excel it says that I have too many arguments and manually seems to never match what the expected answer is supposed to be.

Sorry for the dumb question, I just want to understand this concept because I've been scouring youtube for help and nothing I try works.