Upgrade apps for iTunes and iMove

Per Apple suggestions yesterday I downloaded and installed Yosemite 10.10.5, My Mac has two memory slots of 800 MHz DDR2 SDDRAM, 2.4GHz Intel Core 2 Duo Processor. I was having difficulty syncing my shared iMovie videos on iTunes to my iPad. It never occurred until yesterday. Apple Support had me drag the movie to my iPad, which worked, but they recommended that I down load and install Yosemite so iTunes and iMovie would run smoother, which I did. They also suggested that I go to the App Store and download free versions of iTunes, iMovie, etc. I did but not sure where I went was correct. They showed ratings for these and the ratings were not stellar. Perhaps someone can direct me to the correct place for these issues. They also suggested that I take an iCloud course at the local Apple Store. How can I obtain free upgrades to my iTunes, iMovie, and iPhoto?