You need to start with one problem and wait for an answer before you pepper us with more questions. Searching is also a valuable tool for finding detailed answers that already exist.
It is important to note that if you're using legacy equipment, you need a coaxial cable for each tuner, not each receiver. Most DVRs feature two tuners so they will beg for two cables. You can run with a single cable, but you'll not be able to watch one channel and record another.
Another thing you need to know: DIRECTV doesn't allow for new DIY installs (they won't create a new account based on a DIY install). If you want to do a DIY, you need to go through an authorized installing DIRECTV dealer and beg them to allow you to DIY.