How can I create a New project & Solution in the same, existing , directory? No matter what I do, it keeps creating a new (sub)directory for the project and populating that
To create a solution in an existing directory, I have found the best way is to create it one directory back from where you actually want it, then use the name of the directory where you really want it as the name of the solution.
If that isn't the name you want (i.e. you don't want your solution name to match the name of the directory it is in) then once you have created it, you can rename the solution by right-clicking on it and choosing "Rename". It does not rename the directory it is in nor move it. That is by far the simplest way.
You can obviously use the same trick for a project too, however if you have more than one project in a single directory, ideally the intermediate directory into which they build should differ, otherwise you are going to have issues if you want to rebuild just one of them and it clears out the intermediate target directory.