Every body that has a net charge radiates an electric field, called an e-field. These e-field are vectors. They have magnitude and direction. The magnitude is calculated from the equation below.
The direction of the field is simple to determine with a single, stationary, point charge in space. It is the direction a positive charge would travel. Another words the field points away from positive charges and towards negative charges.
If multiple charges are present then the DIRECTION of the e-field is determined by:
Finding the direction of the e-field due each point, (one at a time.)
Breaking up the e-field vectors into horizontal and vertical components.
Adding up these components to find the net e-field's horizontal and vertical component -like you have done previously with free body diagrams.
Make a solution triangle to calculate the e-field's magnitude and direction.
This video shows you how to find the net e-field due to 2 charges by finding each e-field's magnitude and direction followed by adding these up vectorially.