I would love to give a definitive answer but everybody has their own way of looking after their cars. I am at a point where I am pretty excessive so always struggle to answer these type of questions. I think like myself and most on here, the best thing to do is go on a site like detailing world and read up on guides and products on there. You will find after time your own preferred methods and products, that is all part of the fun of detailing.
Just as a start for you, washing the car every 1-2 weeks is spot on. Ensure it is a 2 bucket method hand wash (google it) and use a good wash applicator like a dooka wash mitt or microfibre madness mitt, DO NOT use a sponge, all these achieve is micro scratches as they don't pick dirt up but simply drag it along your paint work.
Get a good shampoo, plenty out there such as waxaddict, ODK, Carchem and britemax. For your maintenance washes get a nice spray detailer to return the just waxed look. Plenty of good ones out there such as adams, lucas slick mist, bouncers done and dusted.
You shouldn't be polishing your car anymore than 1-2 times per year and remember polishing removes any wax or sealant protection you have on the car. It really depends on the wax, some last as long as 6+ months, others less than 1. Read what the manufacturer claims as a guide but if you are topping it up with your quick detailer each wash it should last a little longer but really, wax as much as you like. I usually wax my car every few weeks if the weather permits it.
Full detail/decontamination I do 2 per year. 1 usually around spring time and the other in preparation for the winter.