Help me.....

Yeah, you probably won't understand a ton of things. It's full of references to older Macross works, mostly SDF and to a lesser extent 7.

Alternative versions: for the first episode, watch the Yakh! Deculture version - that's by far the longest cut of it as it unifies the previous Deculture and TV version scenes. Then just watch the endings to the latter two since they do differ.

The movies are a completely alternate retelling of the story so they are worth a watch. Just remember that with Macross the rule is most movies are always a retelling, not a compilation (Plus is the exception to this rule but it also has new scenes the OVA doesn't have).

Side material - as long as it's manga, not required reading. Not in the slightest. Macross is anime-original and anything you need to see is, in fact, anime. The "Ore no uta o kike!" movie is tied to the chronologically previous show, Macross 7, so if you really have to start now with Frontier, and decide to expand into the franchise - hold that one off until you watch 7.

Anyways, I think Macross is a package and SDF (yes the 1982 original) is the only true point where to start from. It's an iconic show for both the mecha genre as well as idol series (and remember this: Macross is strongest when it has good idols and good mecha scenes).