well then what would u suggest starting with?
im not very strong at all
Do you have access to a weight set? Are you looking to buy? then maybe if a friend has a set you can experiment with to figure out where you are at?
It really depends on the exercises you are doing. Like starting with 15 lbs on a lateral row is a lot easier than a 15 lb curl. But then you may never be able to do a 15 lb lateral raise (try a few -demonstrated in my last answer- with the 5lb).
Whatever weight you start with (and I did have a friend with very little upper body strentgh whose trainer started her with zero in order to first teach her form), you should be able to do 8 reps with reps #7 & 8 being a real struggle.
If you are looking to buy weights you are going to need several different sizes and I find that the "inbetween" sizes (7 1/2, 12 1/2) are very helpful when increasing weight.
I would also HIGHLY recommend checking craigslist and used sports equipment stores (Like Play it Again Sports). Weights are weights; they may look dirty, the paint may be chipped, but a 20 lb weight is a 20 lb weight no matter what it looks like. You can save a buttload of money by buying used.
You can get some dumbell bars and plates for cheap (where you can increase and decrease the weight of the dumbell by adding plates) to start with, but I prefer separate dumbells, especially if you have to rest them on your thighs to get into position (no getting "stabbed" by the bar). However, you may do just fine with the bars, like these for a while.