If you want stability and limited personal liability a corporate set up is good. A corporation is considered as having a personality its own an artificial person with an identity separate and different from its owners who are called the stockholders. As such you as a stockholder are not personally liable for corporate debts. Even if the stockholders quarrel among themselves with some leaving the company yet the corporation will continue to operate.
There are online options for purchasing business forms. Usually the fee is much lower than purchasing them from a store. Simply typing in the kind of form that is required will result in multiple websites that offer the forms for sale. Whether the legal forms are created or purchased they are a necessity and will be used in day to day business activities.
I have seen many well-run partnership businesses with potentials for expansion suddenly closing shop or for sale just because the partners have misunderstanding between and among themselves which had affected business operations.