Hi Ceagan!
Welcome to KittyCats!
As far as auctions go, there's a calendar
here but some of the auction schedules have changed so I'd recommend joining one of the KittyCats auction groups. They usually have postings shortly before the auctions start. Once you find a few places you like, you can pick up a schedule of that location's auctions.
For desirable traits, it's kind of hard to say. I'd recommend that you focus on breeding the kitties that you find the most interesting.
We don't really have bad traits, but some combinations are popular at different times. A mysterious combination seems to do well in my experience (mysterious eye, ears and tail) as does almost any eye trait. Some really rare eyes can give you more value, but I've done reasonably well with the ice eyes, most of which aren't really that rare (although blue ice is kind of rare). I think you got an Odessey Sorbet at auction the other day. Those are pretty popular, especially on a lighter fur and especially in combination with other eye traits. Actually, most of the Odessey eyes are pretty popular. For furs, Russians, Snowshoes and Siamese seem to be desirable, but the different colors have huge differences in rarity. The most expensive cat I own is a Silver Tabby that has awesome traits, though, so there are no hard set rules. I'd recommend sitting in some auctions and just watching what sells. What kitties are starting bidwars?
You'll probably have more fun (and be more successful) if you focus on the kitties that you love. I love Vampire kitties (Mysterious Passion Eyes). They're not everyone's cup o' tea, but I have strong Passion eyes in my kitties for those who like that sort of thing.
Good luck and I look forward to seeing you around!