Which "your"? There are umpteen instances of "your" in that paragraph.
I've made bold the two subj-verb agr errors I think you mean (since Sra gave them to you earlier). And I think you're right about the parallelism error.
Paragraph 2: When most people think of swimming, they think of the crawl stroke. It involves flutter kicking with your legs as you pull yourself through the water with your arms while alternating your breathing from side to side. The most important part of the crawl stroke is the pull, so strength in the arms are important. The motion of the arms are hand-over-hand. To do the pull, start with the left arm bent at the elbow with the hand pointed down to your hip while the right hand is stretched out in front of you. Pull the hand down through the water until it brush your right thigh. At the same time, bring your right elbow up and reach out in front of you with your right hand. Then repeat the pattern. To me, the hardest part of the crawl stroke is getting the rhythm of your breathing down. A typical pattern is right-arm pull, left-arm pull, right-arm pull and breathe on the left side; followed by left-arm pull, right-arm pull, left-arm pull while breathing on the right side.