As Bob stated, you need experience to do the job correctly, ...and generally speaking Experience is something you gain after you need it!
Also, much of that is going to depend on whether you are going to install the material correctly, -or just install it. Items like crimping the seat cover vs hog-ringing it, folding edges correctly, compressing the springs to the correct height, tufting, etc. all that take time. If you are gonna do it right, you better take that "end" off of 'week'.