Head pressure or tightness when i stand or start moving for almost 2 months but its less than it used to be is it brain tumor im 20yo no head injury !

Unlikely: Brain tumors are relatively rare and other causes (especially of transient head pain) are much more common. However since this is been going on for two months it would be worth getting checked out.

Not very high: Without more findings or info, concern of a brain tumor, either benign or malignant is fairly low. While brain tumors may present many different ways depending on where in the brain they develop, headaches are still most common finding. Still, they r rarer than most other causes of headaches. If it persists, worsens, or other symptoms develop, follow up with your md.Dehydration is likely.