Undergrad Differential Geometry Help

I’m working through a set of undergraduate-level differential geometry exercises and need clear, step-by-step solutions together with concise explanations of the underlying concepts. The tasks cover typical topics such as manifolds, tangent spaces, curvature, geodesics and coordinate transformations... (Budget: $30 - $250 USD, Jobs: Calculus, Education & Tutoring, Engineering, Geometry, Mathematics, Matlab and Mathematica, Physics)