Difficult to give exact recommendations, but explore the materials left from the MOOC era, roughly 2012-2017, when high quality online education was provided for free. For example:

- https://ocw.mit.edu/courses/6-0001-introduction-to-computer-... (https://learn.mit.edu/courses/course-v1:MITxT+6.00.1x) and https://ocw.mit.edu/courses/6-0002-introduction-to-computati... (https://learn.mit.edu/courses/course-v1:MITxT+6.00.2x) which are introductions to thinking in terms of algorithms and to numerical analysis in Python. The code assignments with tests are still available, but I don't know whether they run standalone, and how much work they'll need to update them to newer Python

- https://www.edx.org/learn/coding/university-of-british-colum... and https://www.edx.org/learn/coding/university-of-british-colum... which is an introduction to functional programming where you build space invaders game (or at least that was the game you built in early runs of these courses) in Racket (Lisp/Scheme like language)

- https://computationstructures.org/ this course builds a CPU from the basic gates, and introduces many of the computer science topics. The site even has the lab simulations available, but I don't know whether they are still working

- https://learn.mit.edu/courses/course-v1:MITxT+18.01.1x https://learn.mit.edu/courses/course-v1:MITxT+18.01.2x mathematical analysis