Ok, so it is a metal sided pool with a separate liner, and a small pump/filter combo. correct? I think these are 4 feet high, so I calculated your pool volume at 4600 gallons, using a water depth of 3.5 feet.
1) add 2 1/2 cups of 6% bleach (unscented or regular scent) to get your FC to 2ppm. Test your water every evening and add enough bleach to get back to 2 (your target range is 1-3 ppm for now.) Pour it slowly in front of the return (where the water returns to the pool) and it will mix right in. Add the first dose of bleach now, but usually add your bleach in the evening.
2)Get some CYA (Cyanuric Acid, aka stabilizer) and put 2 cups in an old sock. Tie this onto your ladder, preferable in front of the return. CYA is sunscreen for your chlorine, and will keep it from burning off as fast in the sun.
3)) get yourself a test kit. The one in my sig is the Cadillac... well worth the investment, and you will make up for the cost many times over in the savings from using the BBB method. Taylor makes one and Leslie's sells their brand, which is made by Taylor, but the TF100 is by far the best value! An HTH 6-way from wal-mart will do for now!
4)) check out the links in my signature, and get one of the calculators. It will help you figure out how much bleach to add each evening, and lots of other things.
5)) After you get your kit, post a complete set of numbers and we can help you further.
FC, TC, CYA (this will be 0, don't even bother), pH, TA
6)) read all the stickies, link is in my signature!
You can swim after a few minutes of adding the bleach. If you are consistant about testing and adding bleach every day, you will find you will rarely need to shock your pool.