How do I test my game as if I'm playing for the first time?

I’m making a tutorial for my game that only shows up if you’re new. I want to know if it is possible to test if it is working without having to make a new account.

You can use the Run service to detect if you are playing in studio, then wrap player loading and saving functions so you don’t touch datastores.

if game:GetService("RunService"):IsStudio() then
    -- give default data
else
    -- load player data
end

Like @gertkeno said, but you also need a system that properly addresses that. For example DataStore2 has a built-in feature to avoid messing with datastores if you’re in the studio. My datastore has a reset function so your data gets reset like a new player. Your datastore could have a function that instead of resetting, it just loads the default data instead of actual data. However you need a good datastore system to easily make that unlike most youtube tutorials on leaderstats and datastores.
With my datastore if I load default values it’ll save still, so to avoid that I can easily prevent saving in studio and probably should add that functionality.