Here you will find links to resources such as grammar explanations, worksheets, and online practice related to parallel structure in English.
A good place to start is this short video from Smrt English.
Study.com also features a video: Parallelism: How to Write and Identify Parallel Sentences, but requires signing up for a free trial to view.
A less polished video, but with plenty of example sentences is Parallelism in Grammar.
Purdue’s OWL has a great primer for Parallel Structure including some proofreading tips.
The University of Toronto has put together a pdf on Faulty Parallelism.
Grammarly features a page on Parallelism in Writing in its handbook.