Different Gods for different things.
So first tell your interest.
Lord Shiva and Lord Vishnu are the creation one.
Lord Brahma is for knowledge and intelligence.
And like this so on. You can find this out on Google too.
Although due to the nature of the Hindu gods, I would venture as far as to say that most of them are heavily magical. Working with them from a Left Hand Path perspective(the reason I bring up the LHP is because it is more ''magic'' and less ''mysticism'') in those currents is pretty great.
Kali is one of the most powerful goddesses out there, Ganesha has similar functions to Hecate, Hermes, and Papa Legba and other crossroad gods but goesbeyond that, Hanuman can help you as well, Agni can burn away obstacles, Vishnu has so many functions it's surreal...
Brahma is the Generator or creator Vishnu is the operator or preserver and Shiva is the destroyer of evil or great spirit. They make up the Trinity and acronym G.O.D. Ganesh Is a combination of all things to make an embodiment of the one unmanifest supreme God or The all father/mother. _Nithyanadam.