Getting around in Rotorua

Hello, will be going to Rotorua for a conference and would like to go to the lakes (Blue Lake or Lake Okareka, which one do you recommend for hiking and a bit of dipping?)

I probably won't be renting a car (might do, if necessary), but how do I get from Rotorua centre to these lakes? I might go for an Uber but I don't know if drivers would go that deep into the wilderness.

Thanks guys, can't wait to be there!