I'm a forensic science instructor with a forensic medicine degree. Anatomy & Physiology I and II, toxicology, statistics (you've probably already taken this), forensic biology, and medicolegal or medical death investigations will probably be helpful to you. You can audit courses at Coursera, edX, and OpenLearn. Khan Academy is another good one as someone mentioned above. The most detailed course I took on how the body processes alcohol and other drugs was a substance abuse counseling course. I think a subscription to The Great Courses is worth it. They have college-level lectures on several different sub-fields of biology and chemistry, a Medical School for Everyone course, and some new forensic science courses.
Graduate of Not VUL or ENEB
MS, MSS and Graduate Cert
AAS, AS, BA, and BS
CLEP
Intro Psych 70, US His I 64, Intro Soc 63, Intro Edu Psych 70, A&I Lit 64, Bio 68, Prin Man 69, Prin Mar 68
DSST
Life Dev Psych 62, Fund Coun 68, Intro Comp 469, Intro Astr 56, Env & Hum 70, HTYH 456, MIS 451, Prin Sup 453, HRM 62, Bus Eth 458
ALEKS
Int Alg, Coll Alg
TEEX
4 credits
TECEP
Fed Inc Tax, Sci of Nutr, Micro, Strat Man, Med Term, Pub Relations
CSU
Sys Analysis & Design, Programming, Cyber
SL
Intro to Comm, Microbio, Acc I
Uexcel
A&P
Davar
Macro, Intro to Fin, Man Acc
MS, MSS and Graduate Cert
AAS, AS, BA, and BS
CLEP
Intro Psych 70, US His I 64, Intro Soc 63, Intro Edu Psych 70, A&I Lit 64, Bio 68, Prin Man 69, Prin Mar 68
DSST
Life Dev Psych 62, Fund Coun 68, Intro Comp 469, Intro Astr 56, Env & Hum 70, HTYH 456, MIS 451, Prin Sup 453, HRM 62, Bus Eth 458
ALEKS
Int Alg, Coll Alg
TEEX
4 credits
TECEP
Fed Inc Tax, Sci of Nutr, Micro, Strat Man, Med Term, Pub Relations
CSU
Sys Analysis & Design, Programming, Cyber
SL
Intro to Comm, Microbio, Acc I
Uexcel
A&P
Davar
Macro, Intro to Fin, Man Acc