Nomenclature is best learned by starting and getting perfectly clear about naming alkanes. The skeletal structure of any biological compound is based around the saturated hydrocarbons (alkanes). As compounds that contain no functional groups, alkanes are the least reactive parts of the molecule and constitute both the backbone of a compound, its general shape, and obviously its name.
The following series is the basis of systematized naming. It depends only the number of carbons present and the chief functional groups present determines the length of C atoms you are counting..
# of carbons prefix (parent) Substituent representations
1 C meth- CH3-, Me- (methyl)
2 C eth- CH3CH2-, Et- (ethyl)
3 C prop- CH3CH2CH2– , Pr- (either n-Pr or isopropyl) (i-propyl)
4 C but- CH3CH2CH2CH2– (= n-but-); (iso-Bu, sec-but, tert-Bu ) (butyl)
5 C pent- CH3CH2CH2CH2CH2– (pentyl-)
6 C hex- CH3CH2CH2CH2CH2CH2– (hexyl-)
7 C hept- CH3CH2CH2CH2CH2CH2CH2– (heptyl-)
8 C oct- CH3CH2CH2CH2CH2CH2CH2CH2– (octyl-)
9 C non- CH3CH2CH2CH2CH2CH2CH2CH2CH2– (nonyl-)
10 C dec- CH3CH2CH2CH2CH2CH2CH2CH2CH2CH2– (decyl-)