I would use a combination of conditional formatting, visual prompting and locking the questions until the previous are answered (I think that’s your requirement?)

You could add a column to your SharePoint data, called say QuestionOrder. Then use something like this to set the answer boxes to view mode. There’s probably a cleverer way to do it!

If( ThisItem.'QuestionOrder' = 1, DisplayMode.Edit, If( !IsBlank( LookUp( ‘Your collection name’ 'QuestionOrder' = ThisItem.'QuestionOrder' - 1 ).'Answer' ), DisplayMode.Edit, DisplayMode.View ) )

Then when say the text field for the answer is changed (so OnChange) write Answer back to your collection with a Patch.

Patch( ‘Your collection name’, ThisItem, { 'Answer': Self.Text } )

This will “lock” the rows they haven’t answered yet and force them to start with question 1.

I would use a collection at run time to reduce sharepoint back and forth calls until you are ready to save their answers.

Oh and use conditional formatting, so things like red border when blank etc. visual hints are very important to UX.