I haven't seen any good OCA/OCP course, you might need to pick and mix a bit to cover exam topics.
Whizlabs have courses for OCA/OCP but they are quite rubbish, I wouldn't recommend them.
There is a free
Java basics course on cave of programming by John Purcell but it's bit outdated, you would need to learn about lambdas and new Date API from other sources to cover OCA topics.
If you have some money to spend both teamtreehouse and pluralsight have nice courses, they are worth the money if have some free time for studying, if you only have few hours per week then it makes less sense.