Here are the key steps I would take to prepare to start post-secondary training:
1. Research programs and requirements - Learn the admission requirements, prerequisite courses, and overall curriculum structure for the programs I'm interested in. Make sure I understand all necessary steps to apply and be accepted.
2. Improve academic record - Retake any prerequisite courses I did not do well in previously. Maintain strong grades in current coursework to improve my overall GPA.
3. Study for entrance exams - If required for my program(s) of interest, register for and study diligently for exams like the SAT, ACT, or GRE.
4. Gather application materials - Compile transcripts, letters of recommendation, personal statement