I am struggling in naming alkanes,alkenes,...

How do you determine the parent chain? I know it is the longest chain,but there are structures that look quite complicated....the branched ones are counted...!!!!
I am so confused on determining the correct parent chain!!!!!!
Please explain...

When naming alkanes, alkenes, alkynes, yes, it's the longest chain that is first counted.

And then identify the groups attached to to. (For instance methyl, ethyl, etc).

Then number the carbon in the longest chain, starting from the nearest attached group (if it's alkane), and the double/triple bond (if it's alkene/alkyne).

Then name and arrange them alphabetically.

If the structure contains only single bonds (and of course C & H elements only), it is an alkane, and the ending name is -ane. If double bond, it is -ene and triple bond, it is -yne.

These are just the basics. And it's hard to give example when there is no figure, so I really just suggest you read and try doing examples. There are plenty of them online. :)