You can vote both insightful and funny simultaneously, if both are appropriate. This gives it the most points. Insightful is +2, fun is +1, both is +3.
Once you're logged in, check out the 'preferences' page from the link in the top-right.
This is all your user preferences. You can display up to 100 links per page, instead of just 25, that's what I do.
Here you can also unsubscribe from all subs at once if you want to design your subscription list in an opt-in way and choose your own from scratch, rather than the default opt-out way, where you just remove things from your subscription list as you browse /s/subscribed (the link for this is at the very top-left of the screen).
If you have technical problems, you can always message me or even just mention /u/magnora7 in your comment about the problem and that'll guarantee I'll see it.
On the main page, check out the 'new' and 'comments' tabs at the top. These show the newest posts, and the newest comments on the whole site. This will show you everything on the site. More people voting in 'new' is appreciated, because quality stuff has to be voted on a couple times there first to really make it to the front page.
We have an open-source Android app, available on the Android store and F-Droid: https://f-droid.org/en/packages/org.saiditnet.redreader/
There's lots of useful links in the footer as well, at the bottom of every page. Let me know if you have questions.