time is everything,don't lose/loose it.
in this sentence, lose is correct or loose?

The correct word to use is 'lose'.

To understand the difference between the two words look at the Grammar Monster article.

One silly way to remember when to use 'lose' is to compare the two words. You'll see that 'lose' has one less 'o' than 'loose' - you've lost or are missing an 'o'! So if the meaning of your sentence is that something has been lost or is missing, think of the word missing an 'o' so you will always remember to use 'lose'.

wow...!! nyc trick..thank u

Also, you can't use a comma between these two sentences. That would be a run-on sentence. You have to write it like this:

Time is everything. Don't lose it.