Define your own idea of success. It's personal and different for everyone. Your own negativity is your worst enemy with naysayers ranking a close second. You will make mistakes so get over ALL of them now. Mistakes are nothing more than a learning opportunity.
Negative publicity works faster and lasts longer.
Hire professionals to handle the areas of business you do not understand, especially in accounting. The IRS will appreciate it. Develop a marketing plan that uses a variety of techniques and stick with it even when business is booming. Every time you hand out a business card, send a letter or leave behind a brochure make sure it presents a professional image. It doesn't have to be expensive but, if it looks cheap, that's the image the prospect will walk away with.