Also, I see your bike has the rubber-covered-coathanger type of shift lever linkage that was the factory "misstep" of the time. If you find that shifting the bike is causing you grief, you may find that some of our members here have fabricated a fully adjustable, sturdy metal shift linkage with Heim-style joints on either end that I've found are a signficant upgrade in the shifting department.
+1 on all the above - grab the riders manual PDF from our FAQ section and read it to acquaint yourself with the bike, location of various drain holes, oils, etc.
And, do keep your eyes open for scoring one or both of the service manuals mentioned (Haynes, Clymer) - each of them do have some errors in them, but we've mostly all learned where most of them are, and the (2) manuals do cover different topics in different levels of depth.
Don't be afraid to ask questions. Do try to use the search function as best you can (be aware the default search window is only 1 week ago, so you will most likely always have to adjust that when looking for older stuff.)
Most of the R65-specific things are in the Tech section, but there are "gems" scattered throughout. And, we don't mind answering questions - at one time or another, we were each at the stage you are at, though in some cases that was more decades ago than anyone will admit!