Thank you for your interest in Test Studio.
Actually there is no common guidance on the suggested topics as there are few possible options and it is up to you and the requirements you need to cover. However, I will share some ideas with you and we can continue the discussion then in any of the mentioned directions.
I noticed you have activated trial for Test Studio Ultimate product, which includes both the standalone application and the Visual Studio plugin. So, first step should be to decide which of the two products will suit you better - here you can find a list of the supported features
in both licences to help you decide which will better cover your needs.
In both cases - whether you decide to go for the standalone application or the Visual Studio plugin, you need to have a separate project for the tests. Here
is how to create a project in Test Studio standalone and here
is the same in Visual Studio plugin. I will recommend you keep the Visual Studio plugin test project separated from the web app solution to avoid any possible errors in the development process, which are not related to the tests. Basically, the test project is not using the source code of the page, so it is not required to keep these in the same solution.
I hope the above information will be helpful for you to decide where to start. Though, in case you still have any doubts and need additional assistance, please do not hesitate to get back to me with any questions on the topic.