Hello,
Beginner here with a basic question
When do you use a Try and catch block in a program?Do you have to use try catch to make your pgm look more professional ?

try catch block is used to avoid termination of program in the runtime
try catch block is mainly used for database application
its nice way to use database application b'coz if any automatic or any runtime error causes termination of a program then there might be chances of crash in the databases

so if any error raised means we can catch in catch block and we can close the database in the catch block

Actually try-catch-finally block is used to catch any errors/exceptions. It prevents your application from terminating unexpectedly and allows you to handle the errors.

That's pretty much it in a nutshell. Another specific use not mentioned that I like to apply try..catch(try..except) blocks for is datatype checking. eg:

try
casttosomething(variable)
except
messagebox(invalid datatype, please enter a valid type)
end

Something like that checks to make sure a user input was a valid type, quite useful for data integrity.