The very first symbol/imagery will be the Lamb.
Yes, the Spotless Lamb of God!
The Lamb represents Jesus!
Click on the link below for any of the articles in this How to Understand Bible Symbols and Imagery:
How to Understand Bible Symbols and Imagery 01
How to Understand Bible Symbols and Imagery 02
How to Understand Bible Symbols and Imagery 03
John 1:29 The next day John seeth Jesus coming unto him, and saith, Behold the Lamb of God, which taketh away the sin of the world.
Now if you would like to learn to draw your own lamb, you can follow the simple instructions found here.
And for further Bible Symbols and Imagery you can find more here.