On Tikkl you can run pre- and post-event campaigns like surveys and feedbacks. A Questionnaire form can be created separately for this purpose after creating an event.
To create a Questionnaire form separately, after creating an event, follow the steps below.
Click the CREATE NEW button on the Admin page and go to the Basic Campaigns tab and choose the Questionnaire Form template. Then from the Design Campaign tab, fill the details in each tab:
Landing Page-> Questionnaire Form -> Receipt Email -> Settings
You can always preview your survey or feedback form by clicking on the ‘VIEW SITE’ before publishing, and then click on ‘PUBLISH’ button at the top right corner of the campaign to go live.
This also answers the query of "whether I can skip the Questionnaire form while creating an event, and could I do it separately".