Via Settings > Forms
Under the Settings > Forms tab, you can switch the status to Disabled from Enabled and this will archive your form.
Archiving will de-activate your form – hiding it from public view – while retaining all submissions.
You can also switch the status to Disabled from Enabled under the from editing page.
You can scroll down and select "View Disabled Forms" to see a list of disabled forms. After that, you may select "Enable" for any form you want to re-enable.