There are 2 ways to mine. One is with GPU mining and the other is with something called an ASIC.
If you want to use your computer, then you need to buy some type of mid-range GPU like an RX 570 at least and you can mine ETH with that. Profitability is very low at the moment keep in mind, like $0.25/day/gpu. If you got a modern type of PC then most likely your motherboard has at least 2 slots so you can at the very least have 2 GPUs in there. There are some motherboards you can buy that got up to 12 slots or so just dedicated for mining.
An ASIC is basically simpler to set up. You basically buy something called an Antminer S9 and just plug it in and you are all set. All you need to do is pick a pool and a payment address and just leave it running. They are VERY LOUD like a Vacuum cleaner keep in mind. But they are pretty compact and don't take up too much room. Besides the ASIC you will need sometype of PSU. Some sellers might include a PSU with the purchase however.
There are many guides and youtube vidoes these days on how to mine. Just search and it will show you step by step the process.
Well, there's also CPU mining (RandomX and others), and FPGA mining. TBH there are a lot of variables these days, even given the benefits of 'free' power.
Noise is a big one - if it's 'free power' in an abandoned factory, chuck in a load of dirt cheap rocket engine asics. If it's 'free power' in your uni dorm, then a CPU miner will be better/quieter/more useful for study too. Either way, check exactly what the circuit is before trying to load it up - 'free power' often means money hasn't been spent on the system, which in turn means the breakers will trip/wiring will burn.