Sure, so these are very different questions, we can take a stab at each one.
1. Creating a DAO
You can easily create your DAO going into the Aragon App (app.aragon.org). That's the easiest way to do it.
Alternatively, you can create your DAO programmatically using the Aragon SDK: https://devs.aragon.org/docs/sdk/examples/client/create-dao
2. Displaying your DAO in a website
If you'd like to display your DAO in a third-party website, you can fetch all DAOs or any details using our SDK: https://devs.aragon.org/docs/sdk/examples/client/get-daos
3. What can you edit in the DAO
You can edit pretty much everything from your DAO, but it all depends on which plugins your DAO has installed.
DAOs are basically a treasury and a permission management system - so every functionality a DAO can do is actually enabled through plugins. And each plugin can be edited/changed as need be through proposals based on what the plugin enables.
So TLDR: what you can edit in your DAO depends on the plugins you have installed and what can be changed within those specific plugins
And the SDK can also support in that so you do it programatically. Changing settings for your plugins is usually done through a DAO proposal with an action (the action being the change you want to implement): https://devs.aragon.org/docs/sdk/examples/tokenVoting-client/create-proposal-with-actions