I have two left feet

[keannu]

Can you apply "two left feet" to sports or any kind of other physical activities except dancing when you are not good at them? If not, what else do you have?

ex)When it comes to dancing, I have two left feet.

[JMurray]

I've only ever heard "two left feet" in relation to dancing but I can imagine it being used in other contexts.
Some other informal terms for physically inept or uncoordinated:
"clumsy clot", "bumbler", "bumblefoot", "stumblebum", "klutz", "bull in a china shop", "butterfingers", "ham-fisted" and as in your earlier post "all thumbs" and "all fingers and thumbs".

not a teacher

[Raymott]

Can you apply "two left feet" to sports or any kind of other physical activities except dancing when you are not good at them? If not, what else do you have?

ex)When it comes to dancing, I have two left feet.

I've never heard it applied to anything but dancing.
If you said, "I can't skate (ski, cycle); I have two left feet", you'd probably be understood. But you could expect as an answer, "Then you probably don't dance either."

[Tdol]

I have heard it used about football, but don't follow it so can't say how normal this is.

[keannu]

I've only ever heard "two left feet" in relation to dancing but I can imagine it being used in other contexts.
Some other informal terms for physically inept or uncoordinated:
"clumsy clot", "bumbler", "bumblefoot", "stumblebum", "klutz", "bull in a china shop", "butterfingers", "ham-fisted" and as in your earlier post "all thumbs" and "all fingers and thumbs".

not a teacher

Especially for sports, How do you say? Are the expressions "You are a good(poor) athlete" or "motor nerve(this might be anatomical)" or something?

[JMurray]

Especially for sports, How do you say? Are the expressions "You are a good(poor) athlete" or "motor nerve(this might be anatomical)" or something?

Not quite sure what you're looking for here. Of course you can always just say that someone is a fine/top/first class/superior athlete. And on the contrary is a poor/weak/inferior/second-rate athlete, unathletic, uncoordinated etc.
With motor neurons, fast-twitch fibres and the like, you're entering the area of anatomical terminology.