You can remove the navigation buttons at the bottom of the form by setting
the form's Navigation Buttons property (it's in the Format tab) to No.
You can set the form to only allow new data to be entered by setting the
Data Entry property (it's in the Data tab) to Yes. If you do this, and
leave the navigation buttons visible, they will not function anyway!
You can prevent record deletion by setting the Allow Deletions property (in
the Data tab) to No. You can prevent editing existing records by setting
the Allow Edits property to No.
For all these properties, you must have the form itself selected (click on
the small black square at top-left in design mode).
Check it out. Find which approach is best for your specific application