Online gambling is largely unregulated in the U.S. That means the casinos serving U.S. players generally don't answer to anyone. If you have a problem with a casino (like they won't pay you), then you're usually out of luck. I can't count how many players have written to ask me for help because they didn't get paid by some other casino. (Not that I helped them—if a dodgy casino won't pay you then you're on your own.)
You should always place the maximum bet because it makes you eligible to win the grand jackpot prize of 4,000 if you get a royal flush. If you bet with 1 or 2 coins and get a royal flush, the payout will not be proportionally equal. If betting 5 coins is too expensive for your gambling budget, you can find a lot of .25 machines as online casinos usually offer their bets in denominations that include different sizes such as .25, 0.50, 1, 2, 5 and even 10 and 20.
Stick to the proper way of how to play video poker as well as video poker strategy and you won't necessarily be able to become a professional video poker player, but if you're looking for the one casino game besides traditional poker where you can get positive expected value, or at least a very low house advantage giving you hours of play for a very small investment, video poker may be your game.
Slot machines are extremely popular. One of the reasons for their popularity is that they are easy to play. The only skill that is necessary is to be able to insert money into the game and press a button or pull a lever to start play. That is it. From that point on, everything that happens depends on luck. The results of slot machine spins are based totally on randomness. The instant the slot player presses the spin button the result of that spin is locked in. Whether it is (most likely) a loser, a small winner, a moderate winner, or a jackpot winner has already been decided. Slot players can do nothing to change the odds either for or against them.
Winning hands can often be gambled via a ‘higher or lower’ game. UK players will be familiar with this concept as it was used in the popular 70s/80s quiz show ‘Play Your Cards Right’. A single card is dealt and the player must guess if the next card in sequence will be higher or lower. If they choose correctly, their prize is doubled. Choose incorrectly, and all winnings for that hand are lost. Players can usually gamble in this way up to five times in succession.