unable to merge faces together

[0tterBox]

i've tried dissolving the edges but it only gives me an error, i need to merge them into a single face so i can extrude the model, otherwise it makes those patches super wonky and screwed up

https://www.dropbox.com/s/9g119biujia1qxe/faces.JPG?dl=0

[Scre]

u need to learn topology, u got ngon right now u need to work with triangles or even better squares

[still__alive]

I think Scre is probably right. Your large n-gon(s) are very likely the reason it won't extrude right. You don't actually want all those verts to be on a single face at all. The best mesh structure will use as much quads (squares) as possible, with maybe a few triangles.

Here are some decent videos about topology. Some are shorter and sort of give you an idea of what topology is, and the longer ones demonstrate some of the methods of controlling your topology.

EDIT: You don't have to worry about having perfect topology, but cleaning up your topology and getting rid of your massive n-gon(s) as best you can is probably the best/right way of solving your problem.
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https://www.youtube.com/watch?v=VudCtEtNXbI

https://www.youtube.com/watch?v=llOqbJKpK1Y&list=PL13BA7F0F73F78F74&index=16

https://www.youtube.com/watch?v=MBbN__f_pGM

https://www.youtube.com/watch?v=WZL_IrFcNb4

https://www.youtube.com/watch?v=ggADPN06mSk

[Zenogias]

May be you can try to use Boolean tool in Modifyer for the holes,it won't help your mesh so much but it's still better than that.

As scre said your topology is not good at all.