Homer is Ionic, not Attic
 

does that mean I won't be able to read Homer if I only learn Attic Greek. I'm screwed as it will be too hard to learn too many dialects of a dead langugage.

So do I also have to Aeolic and Doric in addition to understand Homer? I just wanted to read a little here and there.

For me to learn this stuff, I'll need to relearn linear algebra to route my vectors in order to reroute my classes of verbs and which dialects have dual and which don't. Might as well learn Linear B as a phonemic, syllabary. Mycenean here I come. Might as well throw in Syriac.

I just wanted to read Homer and the Bible was that too much to ask?

I'm still very much in the learning phases of attic, but I can manage Homer reasonably well. I don't think you'll be hurting too much.

I actually think pure Ionic (like Herodotus) is easier to read than straight Attic because the verbs don't contract as much and it's easier to identify the forms. Homer is his own special set of problems. You'll be fine with an Attic foundation, especially once you get used to Homer's little quirks (like the -oio genitive ending).