Liquidity token

if I liquidity 50% of my token
and before then in ico I sell and airdrop my token
how these tokens give a price
and what happened on not liquidy token

What you are saying makes no sense. However you can create a liquidity pair trough porviders like pancakeswap or spookyswap.

I know
what I say
I want to know if I airdrop my token before liquidity
for example, 50% of the total supply liquidity in pancakeswap , of those tokens was an airdrop
how give a price?

If you airdrop the tokens before initial liquidity another user can provide liquidity first and set prices.
You should airdrop after providing liquidity. You set the price of the tokens when you provide initial liquidity

so i can just presale a token before liquidity ?

yeah you can do whatever you want. but it there is no liquidity no one can buy or sell tokens