Roulette, the simple version
A ball lands on one of the numbered pockets on a spinning wheel, and you bet on where it'll land — on a single number for the biggest payout, or on broader options like red/black, odd/even, or a range of numbers for better odds and a smaller payout. You don't need to understand every bet on the layout to play; sticking to the simple outside bets (red/black, odd/even, high/low) is a completely legitimate way to play.
Craps, the simple version
Craps is built around the roll of two dice, and while the full betting layout looks intimidating, the core bet — the Pass Line — is straightforward: you're betting that the shooter will win. Pass Line has one of the better odds of any bet in the casino, and it's genuinely fine to make only that bet and ignore the rest of the table for your first few sessions.
Why craps tables are so loud
Craps is a shared, social game — everyone at the table is generally betting the same direction as the shooter, so a good roll is a win for most of the table at once, which is exactly why craps tables tend to be the loudest, most energetic spot on the casino floor.
Minimum bets and finding a table
Both games post table minimums clearly on a sign at the table, and minimums vary a lot by casino and time of day — a quieter weekday afternoon typically has lower minimums than a busy Saturday night.