I put a PDF of chapter 4 of my book "Engineering Calculations with Creo Parametric and PTC Mathcad Prime" on my website. It covers the basics of Mathcad:
If you're not aware, Mathcad Express can be downloaded for free from Mathcad.com. You have access to the full version for 30 days and then it reverts to the freemium version.
You can integrate PTC Mathcad worksheets with Creo Parametric models. I have a playlist of videos on the subject here:
I hope this helps with your engineering and design problems.
P.S. I revamped my website so it should be available in multiple languages. Let me know what you think of the translations.