We don’t have any recorded video tutorials I’m afraid, but we have a few step-by-step ones. Here is the latest one, from BTTB12 earlier this year.
We also held tutorials and exercises for Allpix Squared last year, e.g. here and here. These have more of a focus on being exercises to tackle and learn about sensors via that, but it can still be useful. First of all I recommend the BTTB tutorial, however. Feel free to ask if you have any questions. The Mattermost channel can be a very handy place for that, as it is full of Allpix Squared users!