i very much enjoyed your paragraph and the portrait of your family! If you'd like to revise with a focus on only grammatical issues (as opposed to the questions of style and personal taste that mwestwood addresses above), here's where I would start:
There's an article missing in the line "She was a single mom for long time"—the phrase is usually "for a long time." (Articles are tough.)
The sentence "My younger brother is studying in grade 10 at Overfelt high school" sounds grammatically correct to me, but "studying in grade 10" is a phrase that I've heard less often. The more typical way to express that idea might be: "My younger brother is in 10th grade at Overfelt High School." (Also, in the name of the high school, the words "high school" are usually capitalized—so "I go to high school" is just fine, but if you say "I go to Overfelt High School" it has to be capitalized as part of the name "Overfelt High School.")
"He always walks or takes the bus to school because he doesn't has driver" is really close! "Has" should reflect the auxiliary verb "does" (or here "doesn't") next to it: "He always walks or takes the bus to school because he doesn't have driver." "Driver" also needs an article: "he doesn't have a driver."
"He always jokes and tells something funny" is also really close! The only thing is that "tell" usually takes a direct object (meaning you have to tell someone). So how about: "He always jokes and says something funny"? Or maybe "He always jokes and tells me funny things"?
"He is a dynamic and talkative" gives me a great picture of your brother's personality! The only grammar problem here is the article (again, articles are tough). "Dynamic" is an adjective (not a noun) so it doesn't require an article. You can just say, "He is dynamic and talkative."
I understand the phrase "we always spend a good time together" with no problems! I think the more typical phrase, though, is "we always have a good time together."
