http://vergil.chemistry.gatech.edu/notes/index.html

I guess you are asking for something practical, here an excellent guide:

J. B. Foresman and Æ Frisch, Exploring Chemistry with Electronic Structure Methods, 3rd ed., Gaussian, Inc.: Wallingford, CT, 2015.

Also, don't forget YouTube Channels by ADF:

https://www.youtube.com/@AmsterdamModelingSuite

or Schrodinger:

https://www.youtube.com/@SchrodingerTV

Or theory plus practice:

Essentials of Computational Chemistry. Theories and Models. Second Edition. Christopher J. Cramer.

See also Cramer's channel on YouTube:

https://www.youtube.com/@ChemProfCramer

or 'must read' theory:

Modern quantum chemistry introduction to advanced electronic structure theory /. Attila Szabo

or more fundamental courses in quantum mechanics: those given free on YouTube by 'Standford Online' or 'MIT OpenCourseWare'.

And finally, if you don't know where to start, you may ask ChatGPT for something you are interested to learn, we are already in the age of AI.

Best, Pablo

In addition to the literature recommendations by Pablo Mtz , Jensen's textbook on computational chemistry would be "the other classic" besides Cramer's book and I would say it's didactically a bit better structure for a beginner.

For the actual conduction of calculations, there are video tutorials for most relevant packages these days, so just look if the package for which your institute has the license has an official channel.

One addition: if you need DFT, Kieron Burke's classic is accessible for free:

https://archive.org/details/Kieron_Burke_and_friends__The_ABC_of_DFT/mode/2up