What type of foundation should i use?

I have normal to oily skin skin i have redness on my cheeks and spots on my t-zone and along my jaws on side of my face but they aren't that bad.I also have freckles covering most of my face and i have scars on my face fom chickenpox because i only got them a year ago when i was 13 so they were pretty bad on my face. I have quite pale skin aswell.I want an even clear coverage that looks natural but not like my natural skin (if that makes any sense?) and that stays on well and only costs 7 or 8 euro and if you know about anything cheaper that would be great! and if you know of any ways to help me get rid of my spots/scars/redness that would be great and any other advice would be greatly appreciated!