This is a touchy subject, and might be one of the reasons that some people feel too intimidated to sit down and give blackjack a try in a casino, and stick to the familiar slot machines where there is no human interaction. If there is a person who is always giving others advice not requested, smile and move on if you feel uncomfortable. This advice holds for any situation at any table situation which makes you feel uneasy.
Most modern casinos have numerous tables, and there are other casinos nearby.
At no time should you feel intimidated by another player or dealer's words or actions. If a player is rude, obnoxious or drunk, look to the dealer for assistance. If you are a novice, don't be afraid to ask for the dealer's advice first, explaining that you are just learning. If other people don't want to play with a beginner, that is their choice and they can elect to move to a different table themselves. Their job and livelihood depend on it.