As noted, Dragon Age: Origins and Kotor are descendants of pen and paper RPGs. They aren't about real time reactions at all, rather, they center on character builds and proper use of abilities. If that's not your cup of tea, you probably won't enjoy them too much. The stories are decent IMO, if you like the Bioware template.
Some specific advice for Dragon Age:
Go straight to the Mage Tower after leaving Lothering to pick up Wynne, the game's best and for the most part only primary healer, with the exception of a PC Mage. Morrigan can and should be built for support heals to supplement her damage/CC, but even so, it takes time to get her going. Incidentally, if you bring Morrigan to the Mage Tower, DO NOT listen to her advice upon immediately entering. It will result in not getting Wynne.
Positioning is important only so far as you can attack the enemies you need to, hit them in the back if not tanking, not get hit in the back yourself (unless you have abilities to negate back hits), and avoid getting hit with your own or enemy AOEs in a clump.
Tanks: Whether Alistair or the PC you need a 1handed and shield warrior unless you are trying to get very creative (Mages can also tank with proper specialization, but that is probably not a good idea starting out.)
The trick with Warrior tanks is in assigning attributes (STR, DEX, CON) properly. It would stand to reason CON would be the best tank stat but it's really a distant third, all it really does is provide a relatively small health boost. DEX you will need to purchase certain tank skills (plan ahead). STR is, atypically, also a mitigation stat, because armor upgrades require higher strength to wear, and the strength required ramps up quickly (DA: O isn't very well balanced, but that's part of it's throwback charm). In order to keep pace, it takes at least 2 points of strength per level early on. When leveling up I usually alternate between STR, STR, DEX and STR, STR, CON, or maybe even STR, STR, STR if I have fallen behind the curve. Getting stuck in terrible armor can practically scrap a playthrough. Other classes also have some rather unforgiving stat optimizations strategies, but the builds are more intuitive.
Or if you understandably do not want to do research to play video games, just turn down the difficulty.