Journal articles are in journals. Journals are either online or in the library on the shelves.
To find a journal you search the catalogue using the 'journal title' . Find the call number, check the year you want to look at and then go to the shelf to find the journal.
If the journal you find is online you need to use an online journal database. The catalogue record will tell you which databases it is in. You might need a librarians help for this. Please come to the Information desk so the librarian can assist you.