Annotations will help convey the information contained in the Drawing
Keep in mind
Arcs and Slots often times will have Centermarks; sometimes they're automatically added
Notes are used to add text for an endless amount of information to be conveyed to the viewer
Centerlines are often used to indicate an imaginary line through the center of a part or a hole
Balloons are added for callouts to a BOM or a Flagnote
There are many symbols that can be added to provide further detail on your Drawing
Knowing these codes is for Advanced Users
Tables may contain a variety of text that can be customized
GD&T is an advanced way of opening up tolerances for the part manufacturer