I want to start building the pt electric,so, the manual says to use more than one kind of glue to put the plane together. the question here is can i just use apoxy? or i should be using more than one kind for the different kinds of wood?

When building a plane you want to keep it as light as possible and epoxy is very heavy. Use CA glue on balsa. Its light, its fast, and its light.

Use thin CA for gluing where you need it to flow into an area, regular CA for most everything else, and thick CA for filling gaps. Save the epoxy for things like wing joiners

Yes, epoxy will make the plane HEAVY. It's a pain to mix, a pain to apply, and a pain to clean up. You'll have epoxy glopped on and stuck to everything.

You can, in fact, assemble a plane using only medium CA, with epoxy for joining the wings and gluing on the tail surfaces. One 1oz bottle should be more than enough for a plane that size. Remember, a little dab'll do it.

CA is different from "Super Glue" or "Krazy Glue." First off, it's cheaper. Second, it actually works.

If you want, plain yellow carpenter's glue is also perfectly fine for assembling planes. It just takes a little longer.

Some people have allergic reactions to CA.
Use it carefully and make sure you have no adverse reaction. The sensitivity sometimes takes a while to develop, so if you start to notice any reaction quit using it.
Odorless CA is supposed to be better for those who are sensitive, but it costs almost twice as much.
As mentioned, yellow carpenters glue will work fine. You can also find other glues at you LHS.
Have fun with your kit. I built the PT40 (glow) and wa s quite impressed by the quality.