What types of uni should I apply to with my grades??

Getting an A in GCSE maths I don't think would hinder you if you can get A* maths and further at A-level. Yes you have a chance at Oxford if you can get A*A*A with the A*'s in maths and further (the other A presumably in Physics) Doing well in the Oxford aptitude test and STEP would be very useful as well. If you go down the Physics route a full further maths A-level will help you a lot in your first year and beyond.

Go as high in terms of universities as you think you are capable of reaching, ''Shoot for the moon, even if you miss you will land amongst the stars.''

Helppp I got BBBB in maths, chemistry, biology and economics. Would I have a chance to get into Imparial for chem eng?

Also would retaking some modules put me at disadvantage?

Can someone please give me some advice.

For Chemical Engineering Imperial asks for A*A*A or A*AAA... without resits I'm afraid you wouldn't meet those requirements so they would be unlikely to accept you. However, there are plenty of other good universities for Chemical Engineering.