Which sentence has the correct parallel structure?

Not only will I babysit, and I will also try to find a job at the mall.

Not only will I babysit, but I will also try to find a job at the mall.

Either I will babysit, and I will also try to find a job at the mall.

The sentence that has the correct parallel structure is the second option: Not only will I babysit, but I will also try to find a job at the mall. This is the only sentence that correctly uses the correlative conjunctions which is Not only ... but also. The first sentence is incorrect because "and" is not paired with "not only", and the pair of "either" is "or".