Is that posiible to create own Dex in waves like etherum dex?
Yes, definitely. All the tools are there, you can fork the existing client and run your own matcher.
I have read this document thoroughly [https://docs.wavesplatform.com/en/getting-started/getting-started-for-developers.html], tutorials and ride example [https://github.com/wavesplatform/ride-examples] as well but i am confused little bit uncleared about the data storage and transaction nd all contract and ivoke data transaction. could you provide any other tutorial for ride language and invoking methods for example like Dex or other example.