What is the difference between "try" and "try out"?
To try is to make an attempt to do something (or not).
I try not to eat too much saturated fat.
I try to run five miles every day.
To try out can mean either to attempt to qualify for a team sport
Sheila plans to try out for the cheerleading squad.
or, when used with an object, to see whether one wants to qualify something for possible use or purchase.
I'm going to try out a new set of golf clubs Saturday. If I like them I'll buy them.
To "try" something also means to sample it. It is also used as an informal way of ordering a particular food item, whether at a dinner or a restaurant.
I'll try a piece of that peach pie, please.
Try the nachos here. They're supposed to be the best in town.
And, finally, try can be used to mean litigate a case in a court of law
The DA plans to try the case in Superior Court.
or test the mettle of someone or something.
"These are the times that try men's souls." — Thomas Paine, The Crisis
"I find your attitude toward my new wife very trying," John told his sister.
A little bit more context may be helpful. Off the top of my head, I'd use "try" more in a sense of "have a taste" and "try out" like "test if you like a certain activity". Examples:
I've made chocolate chip cookies. Would you like to try some?
Yoga is really relaxing. You should try it out if you want to calm down.
For the latter example, "try" will work, too, but for the former, "try out" sounds odd.