cool is related to physical appearance to look cool and calm is related to mind state.

hello sir i don't know how to speak english? and first you practice to write spelling, learn spelling then try to make short sentences and then further you go.

practice that sentence before you go for conversation.

when thing are far and singular..we use that.

this skrit is for 500

we use those for things that are far and pleural.

we use these for the things that are near and in pleural.

for is not necessary but here for to ask the cost in a way.

both sentence are correct.

before you come and after you go.