There are many pieces of information that you can collect about new clients or leads but you may want to make it as easy as possible for a prospective client to sign up with you.
In Collums, you can choose which data fields to display and which MUST be completed for the client or lead to be created.
Go to Admin>Lists
Click on one of the 3 options relating to choosing fields for creating new clients or leads
You will see a long list of data fields - click the check box to decide which should be shown and which of those MUST be completed to create the new client or lead
Use the 6 dots to the left to drag the data fields up and down the list. This will be the order in which they are shown once you save.