How can I deltete standard apps of the apple watch 4

Such control is not provided at the level you indicate - users/devs cannot delete built-in Apple apps if that's what you are asking. Users can choose to re-order apps, but that is also not under the dev's direct control. Perhaps if you explained the purpose behind your goal someone could suggest a reasonable approach, etc.

Do you want also to remove watch app itself ?

In the same way, there are apps you cannot remove from IOS device.

What you can do is present apps by list and name yours so that they sit at top.