The caveat up front: I have never been a fan of Planet of the Apes. If you're a fan, good for you - but for me, the original film just felt like an "OK" episode of Twilight Zone.
On the other hand, I am a huge fan of Tarzan - and I have to admit that the idea of the two concepts colliding is interesting and worth a look.
I assumed the story would find Tarzan traveling to the alternate reality of the Planet of the Apes - after all, quite a few of his adventures (both by Edgar Rice Burroughs and by other hands) have involved him traveling to different worlds. (I believe someone postulated that Tarzan was a rarity in that he could find doorways to other realities, but I don't remember the source of that concept.)
Instead, we're seeing a version of Tarzan's world that springs from the third Planet of the Apes film (I think), that sent scientist Dr. Zira and her husband back in time to the (then) present day.
Instead of the present, they instead arrive in Africa at the end of the 19th Century, where they settle among the Great Apes - and they adopt Tarzan and raise him as a brother to their own son.
The issue includes snippets of scenes that take place in other times, and it's all a bit confusing.
It's a natural tie to link up the Lord of the Apes with the Planet thereof - but it's hard to see where it all goes from here.
The art is good but the story is a bit of a mush - hopefully future issues will clear things up.