You will quickly learn that the answer to almost EVERY question related to programming and "which is better/faster" is always "It depends". In a nutshell, it is going to be faster to FIND a specific element (I.e the 27th) in an array.
Searching for the element where you don't know the location will be roughly the same for both - unless they are sorted, then an array can be faster.
Inserting a new element in the middle will be faster in a linked list...although I'm not sure if that is still true if you have to find the spot to insert it.
In short, there is no simple answer to the question as stated.
There are only two hard things in computer science: cache invalidation, naming things, and off-by-one errors