If you want to learn 3.5e and have a good time in your first couple games I suggest you avoid anything other than fighter, ranger, or barbarian for your first couple of games. Also you should probably start your first game feeling confident in your understanding of attack rolls; and what modifies them, armor class, saves, how your equipment works, how your class abilities works, what actions you can take in combat, and how to role skill checks. This should only take about 25-40 minutes to figure out and is all you really need to play. You'll probably start picking up the rest of the rules along the way.
One of the biggest mistakes I made when starting to play D&D was playing a wizard my first game. I died on the first turn of combat without having cast a single spell. I was then ridiculed by the DM and players for not having cast mage armor before we went into the dungeon. (I didn't even know there was a mage armor spell) I didn't play D&D for a year after that because the experience was so off putting. Try to avoid groups made up exclusively of dicks, it'll make your first game less traumatizing than mine.
tl:dr If you avoid everything except for fighter, ranger, and barbarian it should only take 35ish minutes to learn to play competently at low levels. Try to find a kind group for your first couple of games.
