i'm new on civicrm and try to export specific contacts. I found the search menu to select the data and i made an export with " Export PRIMARY contact fields" but some fields are not in the export. How i could select all the fields of my contacts create on the civicrm database. Thanks for your Help. Marilyn
Welcome to stack exchange. There are some other questions that may provide you with some answers. Before asking a question you should always do a search. Try searching for "export all data". Also it would be worth saying why you want to do this export. It seems an odd thing to do with a new site.
But to help you, "Export PRIMARY contact fields" is a particular set of fields chosen by someone else and rather general. If you choose "select fields for export, you can chose whatever you want. A bit tedious for all fields, but you can save the selection for later use.
Be aware that you can't export multi-value custom fields this way (though you can get a report to do this.