Hello,
My name is Brandon. I'm new to programming, and I just started a course at college where I must write a C program. The only other program I've written was the helloworld program. I am having trouble completing my first assignment. I have tried for hours to get it to work properly, but im getting errors, and strange outputs. Basically, I am to write an app that helps estimate how much it would cost to paint a room. here is the description the teacher gave me:

You are to write a program to assist a painting contractor to prepare quotes for painting jobs. The quotes are NOT to include HST. The painter always applies 2 coats of paint to areas being painted. Painting costs depend on area to be painted and quality of paint to be used. 1 or more rooms may be painted. You can assume all walls to be painted have a height of 8 feet. Ceilings are painted using a basic grade of paint at $20 per 400 square feet. Wall paint also covers 400 square feet and 3 qualities of wall paint are available; premium at $40, regular at $30 and basic at $20. Labour costs include a setup cost of $100 plus $40 per 200 square feet (includes 2 coats) to be painted. Paint is obtained in bulk so the quote is to only include paint used. An error message is to be displayed if any invalid input is entered and input is to be prompted for and re-input until valid.

here is the code I've already written:
Code:
main() { /*Written by Brandon Benyacar*/

    int area, labour, length, width, height=8, ceiling, setup=100, paint;
    float total, room=;

    {printf("Painting Cost Estimator \n Enter length of room in feet: \n"); /*prompt user to input values*/
        scanf("%d", &length);
    printf("Enter width of room in feet: \n ");
        scanf("%d", &width);
    printf("Please select grade of paint to use for walls: \n 1 - Basic \n 2 - Regular \n 3 - Premium \n");
        scanf("%d", &paint);
    if(paint<=0 || paint>3) printf("Please select a grade of paint that actually exists!!! \n");
    printf("Enter if ceiling is to be painted: \n 1 Yes \n 2 No \n");
    scanf("%d", &ceiling);}
    
    {if(ceiling==1 &ceiling=(length*width)); /* Define whether ceiling is to be included in cost*/
    if(ceiling==2 &ceiling=0);}

{if(paint==1 &paint=20);    /*assign cost to paint*/
if(paint==2 &paint=30);
if(paint==3 &paint=40);}

{area=(2*length*height)+(2*width*height)+ceiling;
printf("%d sq.feet \n", area);}
room=((area400)*paint);
printf ("Total %d", room);
 }
I realise I am nowhere near complete, but I wanted to make sure I got rid of any errors now before I continue.
Thanks in advanced for your help!