>>3-5
There's really no hurry, threads are not pruned and we can start with introductory material.
8.01 is available with lectures videos at MIT OCW
https://ocw.mit.edu/courses/physics/8-01sc-classical-mechanics-fall-2016/
and EDX (archived, you must log in)
https://courses.edx.org//courses/course-v1:MITx+8.01.1x+3T2019/course/
https://courses.edx.org//courses/course-v1:MITx+8.01.2x+3T2019a/course/
https://courses.edx.org//courses/course-v1:MITx+8.01.3x+3T2019a/course/
For a calculus refresher:
https://www.coursera.org/learn/discrete-calculus
https://ocw.mit.edu/courses/mathematics/18-01sc-single-variable-calculus-fall-2010/
https://ocw.mit.edu/courses/mathematics/18-02sc-multivariable-calculus-fall-2010/
And then 18.03
https://ocw.mit.edu/courses/mathematics/18-03sc-differential-equations-fall-2011/
No deadline.