Making a Form in SharePoint through VS

Today was my first day at an intern and I'll have to work with SharePoint through code in order to use to Business Intelligence. I have never worked before with SharePoint and unfortunately I have no clue how to make a Form, which is what I'll be making first in SharePoint. How can I make a simple form with Name, Gender (having to choose between Male and Female) and Birth Date? Thank you! (Everything has to be made in code through Visual Studio!)