Do I need to go to a dentist to be fitted for false teeth?

Absolutely! A dentist will first check your mouth to be sure it's healthy so dentures can be made. Sometimes conditions must be corrected in the mouth before moulds can be made so the dentures will fit properly when made. The dentist will take records of your mouth and recommend the color, materials and shape of the teeth so the final result works right and looks natural for your face.
Yes. In the USA only a licensed dentist can prescribe and "fit" you with dentures (false teeth). However, in most cases, a dentist will send your impessions (molds) and his instuctions directly to a denture dental laboratory, that will ultimately fabricate the dentures. The lab will in turn send the final dentures back to the dentist for final delivery and intraoral (inside the mouth) adjustments.
Yes. It is essential that you see a dentist as there are many treatment options that dentists have as well as the need for surgical procedures which can make you wear your dentures more comfortably.
YES. Not possible to have anything made other than custom-made by a dentist. Can't make your own if you actually want to wear them. Need a dentist to get the impressions, correct bite, and a comfortable fit.
No. You also don't need to go to a mechanic to fix your broken car. However, there is a reason experts are 'experts'. If you want quality care, proper treatment, and the best result, i'd recommend a trained medical professional. Don't you believe you're worth it to have a medical professional do this for you? I do.
Yes. Dentists have the education and training required to properly diagnose and treat your missing teeth.
Yes. While some states allow someone with very limited training to make dentures, you need a dentist to determine that your gums are healthy enough to start wearing dentures. They will make sure the bone underneath is smooth, all the pieces of teeth are removed, and that the gums are pink and healthy. You will be wearing those dentures for years. Get it done right the first time.
No other way. It sounds to me like you have severe dental problems and haven't seen a dentist for a long time. Step one is to see a dentist for a clinical exam, x-rays, and a consultation to discuss your specific dental situation and treatment options.
Absolutely. See a prosthodontist. They are specialists in this treatment. They will give you all your options for replacing your teeth. You may be pleasantly surprised.