Want to find out how to add additional fields and also add companies and clients with pull downs

We are new to Infusionsoft Community. We have signed up through Robin Robins. We have been in the IT Service business since 1984. I have been with the company since 1985. I will post my questions below:
Need to find out how to add additional fields to contacts and companies. Also, need to find a way to add those fields as a pull-down when adding additional contacts and companies.