The pimples on the forehead are caused by several reasons. Keeping this area absolutely clean is very critical. Make sure donot touch your face often, donot expose your forehead under the sun for a longtime, and cut the hair before your forehead. At the mean time, apply those products with salicylic acid onto the irritated area at least twice a day.
Fix your product into one or two brands favorite. However you need to try different brands and products to choose YOUR best one because everyone’s skin is different from others. I have recommended a set of products to a girl younger than you before, but I think it will also work on you. You can try Shiseido and Clinique together to moisturize the skin while get rid of the blemish problems. However you have to use eye cream everyday to prevent further aging of the skin, also serums are necessary for a person age around 30 (Like the ANR from EL is very good). Pureness is designed for the women age under 25, so you are encouraged to try Skincare from Shiseido. But all their products are good from different regards.
I would be happy if you can explore the product suitable for you in spite of my advice, as I said, everyone is different.
So try to find my suggestion routine which I have posted earlier and good luck!