1. How much disk space one would need to run full node and prune node? (I don't think I have enough space for either of them, 240GB SSS, sad life).
The full node actually is the one that needs more space since it stores all blockchain data’s and many more are still being stored, a 500GB plus should be ok for smooth running, you can just buy HDD instead of SSD since the former is cheaper. As for prune node it depends on the amount of space you want it to use then, I think you can specify it
2. How do we setup a blockchain node? (Again, I have no idea how this works, zero knowledge).
You can use bitcoin core as the software to run a node. Below are links of how to run a node and also where to download the bitcoin core app.
https://bitcoin.org/en/full-nodeYou can download bitcoincore from the link below
https://bitcoincore.org/ and then you install them, here is how to
https://en.bitcoin.it/wiki/Help:Installing_Bitcoin_Core