Database Design question I am currently interning and one of my tasks is to design a relational database model for a wedding firm that plans and handles weddings. 

There is a user log in, and the users will be bride, groom, vendors and guests. I am not exactly sure how I should architect the database as it is the first time I am making one. 

USER (user_id, username, password, bride_id, vendor_id, guest_id) 

BRIDE (bride_id, bride_fname, bride_lname) 

VENDOR (vendor_id, vendor_fname_lname) 

GUEST (guest_id, guest_fname, guest_lname)


This is a somewhat version of the schema I was designing, but I am unsure how I can have everything on the USER table instead of repeating fname, and other redundancies. Also, the reason I have not put everything in the USER table is because I am not sure how it would work out. Can someone please explain this to me?
this needs a lot more information
they are going to have registry, church, and a LOT of other stuff  

you need to read a book on database design or do some tutorials as your design is not very good    

starts with weddings plural
they are not going go want a separate database for each wedding   

if everyone needs to logon then you need one table for that  

wedding:  
ID   PK
brideID   FK to user
groomID   FK to user
vendorID  FK to user


if you can have multiple vendors then need a separate table

user:
weddingID  PK  FK to weddingID
usrID      PK
password 
fname  (vendor just does not have fname) 
lastname 


if they are not brideID, groomID or vendorID then they are a guest