Most articles actually need little text formatting. All formatting is achieved by placing symbols either side of text. You can either type it manually, or add it through the toolbar at the top of the editing area.

Headings and subheadings can be added by clicking  Advanced then Headings 
Alternatively, put text between = signs:
==Heading==
===Subheading===

Text can be made bold or italic using the B and I buttons of the toolbar.
Alternatively, put text between ' apostrophes:
'''bold'''
''italic''
An article's subject is written in bold the first time its mentioned.