I'm studying law, but I want to be a TV director.

When I was a high school student, I joined the cheer-leading club and the science club.

I have (now?) joined the law study circle.

In addition, I'm thinking which circle I joinabout joining the Yosakoi circle and the walking circle.

However, I would only use the word "the" in front of other words, if I had a particular club/ circle in mind. So not just any Yosakoi circle, but one particular Yosakoi circle - the one at my school for example.

My hobby isies are watching TV and eating!

EI especially I like hamburger steak.

In order to speak fluently to be a TV director, I want to study English hard.

Please talk to me with friendly.

As already mentioned in the correction post made by somebody else above, the word friendly should not be used in this case. People would understand you though.

Hello!,

Saying "Hello! Nice to meet you." as two different sentences is fine, but not very smooth. If you combined these two sentences together into "Hello, nice to meet you!", it would sound much better.

I'm Satomi.,

Same here as the first sentence. Try "Im Satomi, and i'm from Hokkaido". Having them as different sentences is ok, but combining them makes them feel smoother.

I'm studying law, but I want to be a TV director.

When I was a high school student, I joinedwas in the cheer-leading club and science club.

It's true that you joined the clubs, but the act of joining isn't really what you mean to say here. The sentence is more about being a member of these clubs.

I have joined a law study circle.

You have joined one law study circle, but many exist, so it's best to say you joined "a law study circle"
Also, while "circle" works here, more commonly used english words are "group", "club" or "organization". Consider using one of those instead.

In addition, I'm thinking which circle Iabout joining Yosakoi circle and or walking circle.

"joining yosakoi circle or walking circle" is the action you're considering. "thinking about ..." is how you'd say that you're considering an action.

My hobby isies are watching TV and eating!

Since you have more than one hobby, use "hobbies" instead.

EI especially I like hamburger steak.

Me too, I just had some for dinner today!

In order to speak fluently to be a TV director, I want to study English hard.

Please talk to me with friekindly.

"friendly" is a descriptive word. It describes actions or behavior, but isn't something that you can have.
You could say "Please be friendly", but "with friendly" isn't really ever used.