Or those WX would be locked until I recieve the

full amount in 1 year?

No — you'll be able to claim WX/USDN every time a new block is added to the Waves blockchain. Thus, the full amount can be received in a year.

By claim you mean I'll be able to withdraw WX and exchange them for another coin for example?

Every time you decide to get your assets from the smart contract, you can take either WX or USDN. Let's say, once the IDO is over, the WX price increases (>1 USDN), so you can take a part of your WX tokens from the smart contract and sell them. Then, after a while, the WX price becomes less than 1 USDN, and you can start taking USDN from the smart contract instead of WX so that you don't lose anything.

The WX token gonna be trader in the future in big exchange like Waves