To change the order of columns in clients' database, in the top menu select CRM > Clients > click on the cog icon > Contacts. Click again on the cog icon and select Display options.
In the popup you can:
change the order of columns
mark with checkbox if you want them displayed
select how many clients are displayed per page
Note! Settings descibed above make changes for the whole account. So if you change eg. the order of columns, it will be displayed like that in each client's card.