First, welcome to the site. I think you are taking the exact right approach. (ie, start with the limited cards in Silver, and start with playing games against Lord Rat.) I think you can play about 5 games in a half-hour against Lord Rat, right? So, I think, even playing just those few games each day, you will pick up the cards much faster than you give yourself credit for. After all, at least 75% of the cards are pretty straightforward. There are cards where the instructions are a bit complicated. And there are some cards that have unusual interactions with other cards. But you'll get there faster than you expect.
Once you have the basic understanding of at least most of your cards, you'll be fine to play real opponents. My advice: Use The Chat function! If you find yourself in a game where you do not recognize a card or two, just tell the other person in chat that you need a minute to read the card. Almost all players remember what they were like when they first started, and they'll be fine with you taking a minute or so at the very beginning, once you have told them your beginner status. (What irritates people, according to posts at this forum, are players who take a long time thinking about each move, or for many many moves in a game.) As long as you move reasonably quickly after the starting phase of the game, I think you'll find that 985 of your opponents will be super-friendly. At least, that's been my experience.
