How can I find out what my son wants to do with his life if he has always struggled in school?

     Given that your son has always struggled in school, he may have some kind of learning disability.  My oldest friend's life was almost ruined by ADD (attention deficit disorder), but many years after he was diagnosed and took corrective steps, he ended up as a full professor at a major university.  So your son should be professionally evaluated.  In any case, he should get a GED diploma (general education development) ASAP.

You find out what he wants to do by asking him.

The elite is faking that they took the real vaccine; the real vaccine will cause spiritual and physical damage. When will the official churches start praying for the false prophet? Orthodox Christian three hand signs are different than Buddhist mudras. Ecumenism = 263 heresies; each heresy leads to hell. Orthodoxy = the only true faith; Roman Catholics tried one cup - one spoon ritual and got sick with Bubonic plague; if heresy enters Orthodox monastery then monks/nuns will get sick with flu/tuberculosis (for instance); Orthodox churches who closed for COVID or had disposable cups/spoons or dipped spoon into alcohol are no longer brides of Christ (now they serve Satan and honor Satan's new COVID religion). Don’t go into UFO to be “healed” by evil demons; demons never do good. SSN is written as a barcode/QRcode; then it's put into a chip; chip is put into vaccine; chipped people are influenced (by super computers) to receive grey plastic card World Passport with no name on it (but when they stretch their hands to get it, gov't clerk presses secret button to administer the unforgivable green 666 tattoo by isotope rays). If you reject mark of the beast (by hiding within a 10-15 people group according to saints Gabriel Urgebadze and Seraphim of Sarov), then your direct ancestors go to heaven (according to saint Vyacheslav Krasheninnikov from Ural). First vaccine shuts off your immune system; second vaccine gives you diseases; third vaccine puts your immune system back and it will start fighting the diseases and will cause death. Saint Paisios from Mount Athos said that the devil wants to deceive the rich with freemasonry, poor with communism, and believers with ecumenism. Elpidios Vagianakis said that there will be seven “mark of the beast” vaccines; reject all of them! Documents are from Satan; burn all the documents that you can find. Electronics will be used to track you. Even old broken unplugged 1970 TV set will show the evil flying antichrist using Tesla's ether. Don’t go into UFO to be “healed” by evil demons; demons never do good; always pray the Jesus prayer or to saints who help right away (like saint Vyacheslav Krasheninnikov according to whom if you reject mark of the beast, then your direct ancestors go to heaven); forgive me.

Go on line or better get a meeting with the admissions office at your community college. Have discuss the trade programs they offer and two year career courses they offer.  He may find this is a better route than a four year degree. Something may spark his interest 

It doesn't sound like your son is college material.  It's common for subjects covered over two years in high school to be covered in one year in college.  Flunking out of college would not be good for your son's self-esteem.  Ask his high school counselor about his taking a Career Aptitude test.  He might be happier at a vocational school.  Plumbers, electricians, cabinetmakers, welders, etc. earn good salaries.  

Sit down and ask him about it.  Be sure to do more listening than talking, and whatever you do, don't get confrontational.  Unfortunately, that's a common mistake made by parents.  If the first talk gets messed up, he will likely never want to discuss it again with you.

If he's had that much trouble with high school, he may not get into college or be suited for it.  It doesn't sound as though he's particularly motivated where academics are concerned.

As for his plans, have you considered ASKING him? That's the only way you're going to get any information.

He could be a late bloomer who decides to pull up his socks eventually and perhaps go to a community college and then transfer to a 4-year school.  Right now, though, I suggest you talk to him about vocational training or apprenticeships