A while ago I wrote about why I like fixed lenses vs zoom lenses. I like fixed lenses because it keeps the creative side of my brain working. Fixed lenses are also cleaner. It suits the style of my photography
So when you start off as a photographer, you face so many choices you become overwhelmed.
My first choice would always fall on to 35mm f1.2 lens. With this lens you can take different types of photos. With a 35mm lense you can take pictures of large groups of people, rooms or buildings, close ups of details and portraits.
It's not an ideal or universal lens but it is a great way to start off. When choosing a lens I would always be concerned about the angle. If you choose a 50mm, standard portrait lens, it may be not wide enough for you in a room full of people.
You should consider what (people, animals, products, scenerey) and where (outside, in a building, in a studio) you are going to be taking pictures.
Experiment, borrow, hire and test. You can find your ideal lens that can be completely different to 35mm f1.2 taking into account your desired style of photography! :)
Below are a couple of examples of a detailed shot, of a building shot and a portrait all shot with 35mm lens!