I'll have to use SPSS in my thesis, so I would like recommendations of SPSS courses on internet. If possible, it would be great if those courses were free (or at least not too expansive).
Prof James Gaskin effectively provides online courses via a series of videos. Refer to his website: http://statwiki.kolobkreations.com/index.php?title=Main_Page.
Linkedin Learning has several online SPSS courses. If your institution pays for access to Linkedin Learning, you can access unlimited content for free. (And there is a lot of high-quality content on their site.) If not, it looks like an individual subscription is $30/month. Perhaps you could get a free trial for one month and that would be adequate along with the other resources mentioned above.