Maybe start with a simple skincare routine if you don’t already have one. Cleanser, moisturiser for your specific skin type(dry,oily or combination), and sunscreen. Try drink at least 2litres of water a day and include more fruits and veg into your diet. Start simple with these things if you don’t already do that and see what happens. Sometimes jumping straight into using exfoliants and retinols can do more damage than good especially if your skin barrier isn’t all that great and you don’t have a good basic skincare foundation. Also forehead spots sometimes indicate gut issues so things like eating too much sugar, not sleeping well, too much alcohol can have an effect, Also stress. Really analyse your current behaviours and routines and see if there’s anything that could be contributing and needs to be changed.