There are plenty of places to park in La Lakota OR the visitor car park at Oasis Park, both free. Or you can catch the bus and get off at Oasis Park and go through the tunnel under the road to get to the camel departure point.
The shaky caravan looks good :) This activity (like some others) has to be booked and paid for separately. Who needs it ... why not ... The Osais Park is so extensive that you cannot see everything in full. Personally, I find the botanical garden the most interesting. But also the camels, or the giraffe facility next door are very worth seeing.