I want to try to custom make my own bicycle, where do I start?

There is no serial number database for those bikes

https://www.google.com/search?q=white+super+chief+bicycle+date+of+manufacture

https://www.google.com/search?q=white%27s+super+chief


..

Congratulations. You are now a hipster.

I don't know if you meant a road bike or you mean an exercise bike, but you can try these websites... http://www.fitnessrepairparts.com/part_search/CatalogSearch/Fitness%20quest , http://bicyclepartt.blogspot.com/2012/08/fitness-quest-recumbent-bicycles-parts.html , http://exercisebikereview.homestead.com/Exercise_Bike_Reviews_Fitness_Quest.html , or type in the Search field: 'Fitness Quest Bicycles and a list of websites that might interest you will appear. Click on their links. Hope this helps.

Try Trek.com, under customer service. IF you have a Trek bike shop in the area, they can be a big help

Contact Sears at University Park mall, Mishawaka Indiana

Assuming this is an older RoadMaster,
try here:
AMF Roadmaster Bicycle Owner Owners Manual Paperback 1975

Current Roadmaster manuals are available from the manufacturer, Pacific, here:
Customer Service

Check with your DMV (department of motor vehicles), not sure about MI, but in a lot of States vehicles with a motor smaller than 51cc does not need to be registered to be street legal. It would then be considered as sports equipment under your homeowners insurance policy (for replacement purposes) like a regular bicycle.

Those are going to be tough to find, but this could be a start:
BIKESDECALS Stickers for bicycles Customized decals and Stickers...
I just Googled "cannondale frame decal"

This seems like the best they have:http://www.diamondback.com/downloads/owners-manuals/ unless you try phoning them at 253-395-1100 and asking for customer service or writing them a letter at DiamondBack Bicycles 6004 South 190th Street, Suite 101 Kent, WA 98032 Hope this helps.

Ascent is a Performance Bicycle house brand. If you call Performance customer service in Chapel Hill NC, they will probably mail you a replacement manual. The email for customer service is [email protected] or you can call 1-800-727-2453