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Depends on your specs. Go to this site and feed it some specs: https://www.coinwarz.com/cryptocurrency?sort=profitusd&dir=desc
You can use reddit to get an idea about how much hash power various GPUs/CPUs provide. My old laptop can do 35-45 CryptoNote hashes with the CPU running MinerGate in the background.

how much is that in USD? My computer sucks so I doubt it would be good for much.

Minergate does have an inbuilt tool that calculates this for you, just running on CPU is around $25 a year, using a graphics card you can usually do around $1-2 a day, minergate however isn't the most profitable as they have been accused of market rigging and points shaving. Personally once you feel comfortable I would just mine XMR directly as this is the most profitable at the moment and has been for a good few months now.