Doing my first Network install for a client!

HI friends! thank you for reading and any advice. I am quoting my very first network cabling job for a client.

I have done cabling at home before but Ill admit it was not any prof job and it wasnt always pretty.

For a client I will only do quality work with a prof appearance so I need advice on the best procedures. Its a small office needed 3-6 100ft runs. they want Ethernet and phone. I was reading I can run phone and fast Ethernet down 1 cable since Ethernet only uses 2 pairs. Is this a viable rout? Should I just run 6 separate cables?

I will need to buy cabling, keystones, wall plates and a punch down tool. Is there a good place to buy these things affordably?

Lastly, I have never dealt with phones, I can run the cable well but there are these wall panels for the phones and i don't know how to punch that stuff down. I think its called a 66 block. anything special I need to know about those?