Need help

Sorry to bother u people, but my brother stopped playing n he gave me the account last week. As a new player with this account u feel clueless. I asked him to guide me but he says figure out on ur own. So I am here expecting some suggestion from u guys. I need help with hydra team. I watched few videos of ash and others n learning slowly but hydra keys am not using since I don’t know who is good for which, any help will be appreciated.