What can I do after being caught with a gram of marijuana and pipe?

You should not confess, cooperate, or consent to a search. That is not how you handle the police, that is how the police handle you. They get most people to allow an illegal search and confess to crimes because they are much smarter than the criminals or young people that they deal with and have a lot of leverage and power to work with. The case will be dismissed if it is a first offense.

Get an attorney, this can affect you for the rest of your life, and we do not usually put people in jail for this as a first offense.

As you probably know, in MA, possession of less than an ounce of marijuana is a civil offense and not a crime. However, as silly as it sounds, possession of paraphernalia is still a crime. If you are concerned about your Criminal Offender Record of Information (CORI), your Record, as you should be, you may well be able to beat this case if there was no stop sign. The issue really is your record. Any mark on your CORI can prevent you from getting a job. Although it is a minor offense, often times employers simply make two pile, those with Records and those without. You know which pile gets further review. If you were charged criminally, by all means I would advise you to hire a lawyer and try to beat this case. I am always amazed when students, who probably will spend upwards of $100-$200K on their education are afraid to hire legal counsel to try to preserve their Record. If there was no stop sign, then the stop could be deemed unwarranted. If that is the case, anything found as the result of the stop would be suppressed and inadmissible in court. That would end the prosecution's case right there. You may even be summonsed into a Clerk's Hearing to see if there was even probable cause to issue a Criminal Complaint. If that is the case, your position is even better. If you are successful at a Clerk's Hearing, no criminal complaint even issues and you have no record a criminal charge whatsoever. Speak with a lawyer as soon as possible.

If the officer did not have a reason to stop you, your lawyer can file a motion to suppress and ask the court to dump the evidence. IF the evidence is suppressed, then the DA has no case. If the DA has no case, then you will not have a charge on your record. On the other hand, you are likely looking at a $100 fine for possession of marijuana (unless the DA files felony transportation charges, which he can but shouldn't). Your choice.

You will be required to do a drug and alcohol screening and attend any treatment they prescribe. Probably pay a fine and do community service.

You should get a lawyer and fight the matter. At the least maybe the person could work out something where you have no conviction on your record. You may be able to get the matter dismissed. This conviction can screw up your life.

Don't plead to anything or agree to accept anything or talk any further with the police without talking to a lawyer. There may be issues to argue regarding the stop that could get the charges reduced, dismissed, or the evidence suppressed. If it is your first drug offense, you may be eligible for a diversion program or a delayed sentencing that would keep the matter off your public record. Consult with an experienced criminal attorney in your area as soon as possible.