I have an Ibanez rg321. The only other electric guitar I have played is a ibanez grg270b. Which has a super low action and came setup with 9s. It is such a breeze to play single notes or do stuff like bar chords.

I changed the strings from the factory 10s to 9s on my rg321. I have adjusted intonation but it has a higher action. I am finding difficulty in adjusting to it. When I play the two I can see the difference.

Now, I would like to adjust the action on rg321 to the super low one that I am used to. But I have no expertise in this and have never done this before. I don't want to end up with something where it becomes totally unplayable or starts buzzing or whatever and then have no knowledge to getting it to a proper setting. Can I possibly do it myself. Can someone help me and offer some advice or word of caution.

One last point is that the rg321 has fender like bridge saddles with two points of adjustment. I have noticed that instead of them being level they are tilted at an angle. The lower three strings (E,A,D) much more so then the higher 3 which are almost level but still slight angle. Is this how it is supposed to be? This is how the guitar was when I bought it new from the shop...

Please advise me thanks!
You can do this. The saddles on your bridge should be level. Equal contact pressure of the legs keeps the buzz away, and the strings centered in their groves. Some use a little superglue or Locktite on these small screws to keep them where they need to be once adjustments have been made.
String height above the frets depends on playing style and feel. Match the other guitar's string height at the twelfth fret for a start. Go from there one string at a time. Strings can be too low.
Intonation, as you know, adjusts by screwing the saddles foreward or back. Be sure to stretch and break in new strings.
Then you get to learn how to adjust the pickups. There's plenty of You tube help with guitar setup. Good luck.