[CF2010]

^ Really not understanding how the two images show the same thing. In the first one, does the CHCH represent CH₂? HOW?!

Can someone draw the structural formula of this please so I can understand it better.

Any other links online that I can further practice with structural and display formula so then I can progress onto nomenclature.

[Wald_ron]

Notation wise, Hydrogens attached to Carbons aren't seen as significant, the only exception to this is when naming fluorinated(C-F) compounds.

With this in mind, the number of Carbons in a Chain is seen as signifigant, in both examples there are seven carbons attached to one another, thus the basis of the nomenclature  (hept-)

Nomenclature is a naming system.