I have never "pre-rinsed" a chamois in soapy water....no need....just regular straight out of the hose water.....get it very wet, then wring it out and use. And contrary to many beliefs, you can just toss a chamois in the washer and clean it up....works great.
As for car washes....touchless ones are okay, but, beware, the pressure from the sprayers may push water in around the window seals or the sunroof (if so equipped).
The biggest things to remember when washing your car
-Surface temp....if the car is sitting in the sun, make sure to rinse it off with cold water long enough to drop the temp of the car and work in sections.
-Wash mitt....rinse it out....get any grit that you may pick up along way out of the mitt.
-Don't let soapy water dry on the car....it's harder to get it off....
-If water does dry on the car and you catch it quickly enough, just use your damp chamois to wipe off the spots...next, some detailer spray, or even a small "spot wax" will work.
-The post that mentioned a "last rinse" with "free flowing" water....good advice....it does work wonders
-Finally....don't worry so much....almost everything you could do to your car while washing it can easily be fixed....I said almost....that doesn't mean you get to hit the car with the nozzle and just wipe it away....lol.
After washing and drying it, get it in the shade/garage for any detail work you will be doing.