scared i have cancer

my testicles often feel a slight aching pain and the left area above them near my bladder often feels uncomfortable aswell as if something is blocking it. I dont feel any lumps anywhere currently, I used to feel a slight lump on my left testicle but it was inconsistant and I am confident it was just skin/ slightly mis-shapen. I am currently going through alot of stress so maybe I have some sort of ulcer or maybe it is just indigestion as my meal times are fairly inconsistent. I do drink and vape but i dont realy see how that impacts testicles but maybe the drinking is affecting my lower stomach. I am only 18 so its just very worrying for me, does anyone know any more signs of testicle/stomach cancer and does anyone know any other possibilitys of what this pain is. Lastly, does anyone know how to get scanned or tested for free?