I have used this stuff and something similar from Extremtextil (the latter wasn't calendered)
Ultra lightweight ripstop nylon. Also referred to as parachute fabric the ripstop grid integrated within the material provides it with extra strength and resistance to tearing. This fabric has a very tight weave providing excellent wind resistance. Its texture is similar to that of silk. Not...
www.profabrics.co.uk
If this is the stuff you have, it is hardly worth making a tarp from it. What I have was calendered, so might be down proof, but not all ripstop like this is. If one side is shiny and one is matt, that is a sign it has been through the heated rollers involved in calendering. It makes it a lot less breathable, but is not waterproof.
Seam sealing will be pointless, even if you Nikwax the material, it will not be waterproof enough that the seams are the week point.
It will fray like crazy over time, so when you make your carry pouches, be sure to turn all seams, in fact, you might want to do an extra fold because the fabric can have a tendency to pull open at the stiches and if your rolled seam is a bit small you can end up with it pulling apart anyway.
The lack of waterproofing can be good, it means that it dries fast. I made a small bag for my wash kit, it doesn't matter that it gets wet, it dries as does the contents. I am partial to zippered pouches, like the Kifaru Pull Outs and stuff by Tuff Possum, but have made them only in silicone, PU and Sil/PU coated material. I used the uncoated fabrics to make clothes stuff bags in my hammock, and some other stuff sacks. A downside of the uncoated fabric is that it breaths enough that you cannot squash the air out of a bundle and have it stay that way while you pack, the way you can with proper roll top dry bags.
It will make a good gear hammock with a no3 zip running the whole length. Dead simple to make, changes the hammock camp experience significantly.
Guterman Sew All will be fine. No70 needle.
Good instruction sources:
Jellyfish
Red OLeary
Tacblades DIY projects
Jason of All Trades