5 things what I should or not do to keep myself healthy

5 Things That I Should or Should Not Do to Keep Myself Healthy

I should sleep eight hours everyday.

I should sleep eight hours every day.
Maybe I shouldn't work in the vegetable garden more of four hours in the morning.

Maybe I shouldn't work in the vegetable garden for more than four house in the morning.
I'm not sure if I should drink or not a cup wine with the lunch and dinner.

I'm not sure if I should drink a cup of wine with lunch and dinner or not.
I shouldn't take off my shirt at the beach. The television advices are alarming in the summer.

I shouldn't take off my shirt at the beach. The advice on television during the summer is alarming.
I have got broken the meniscus.

I have a broken meniscus.

But it hurts not me.

But it doesn't hurt.

The doctor tell me that I should go into the operating room.

The doctor told me that I should have an operation.

So, some friends tell me that I shouldn't accept easily.

But some friends tell me that I shouldn't accept his diagnosis so easily.

I don't know what I should do. (no correction)

A very funny list of shoulds and shouldn'ts!  Is the reason for not taking you shirt off at the beach because of the fear of skin cancer, or the fear of letting people see your belly? :-)

5 things what I should or not do to keep myself healthy

5 Things I Should or Should Not Do to Keep Myself Healthy or
5 Things I Should or Should Not Do To Keep Myself Healthy

In Spanish, titles are written in normal sentence case with only the first word capitalized. In English, we capitalize each word of a title except articles, prepositions, and conjunctions. However, it is very common to see all the words capitalized.

I should sleep eight hours every day.

"Everyday" is an adjective that usually describes something that is routine, dull, or done daily. It is written in front of the activity it describes. "Every day" is the same as "each day".

Maybe I shouldn't work in the vegetable garden more than four hours in the morning.
I'm not sure if I should drink or not a cup wine with the lunch and dinner or not.

I shouldn't take off my shirt at the beach. The television warnings are alarming in the summer.

"Advice" is what a person gives to another person to help them improve something. For example, the corrections you get on italki are advice. A "warning" is similar, but it is something that says "if you do this activity, it will have this bad result."

I have got a torn the meniscus.

Broken is okay, but we "break" hard things such as bones and "tear" soft things such as muscle or cartilage.

But it does not hurt me.

"Me" is okay, but the it is understood and not neccessary -- who else would your torn meniscus hurt?

The doctor tells (he/she tells) me that I should have surgery done.

"Go into the operating room" states your location, but we do not know what you are doing there. Are you a doctor performing surgery on someone? A nurse? The patient? By using "have surgery done" you are stating the treatment that the doctor suggested.

Some friends tell me that I shouldn't accept [shouldn't accept what? The surgery/treatment?] easily. I don't know what I should do.

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As originally written, you were able to express your thoughts clearly -- which is the point of learning a new language. Very good!