Reading the regs will get you started.
Understand the draw process for Oregon has some differences from other states you may/may not be familiar with. The 2nd-5th choice options in the Oregon draw process require leftover tags to be present so a little research will tell ya if you're gonna get a second choice but anything beyond that is futile in most units that are worth hunting.
Most of the desired units to hunt elk in Oregon require a few years to draw..... at least.
Using Hood River as a reference, The White River-Hood unit requires 3 points for a cow tag but you could draw the bull tag every year if you wanted to use the bull tag as first choice.... Or you could apply for the first choice cow tag, with the 1st season bull tag second choice. This would more or less get you the cow tag every 3-4 years and the 1st season bull tag every other year or so in between. If you used 2nd season bull season, you'd draw every year for second choice while building points for the Cow hunt.
This point game is present in a lot of the eastern side units.
The Westside of Cascades is a whole different story and not a game I play so I'll leave that to someone else to weigh in on.
I recommend doing some research on the Hood, and White River units and expand from there based on your interest.