Possession of Drugs falls into two broad categories. Possession for personal use and Possession with Intent to Distribute.
There is discretion that a law enforcement officer has regarding the determination that a person is in possession of drugs in an amount that is consistent with personal use. Once law enforcement determines that this is not personal use, the charges are more severe and carry more significant penalties. Also, the type of drug is significant in what kinds of charging you will be facing. Possession of any amount of Heroin is a felony, while possession of Marijuana (less than 20 grams) is a misdemeanor.
Simple Possession of Marijuana is a misdemeanor where an officer has discretion in whether to arrest or not. And even if charges are brought, there are more options for a favorable resolution on a case like this. If law enforcement believes that the amount is consistent with commercial activities the charges and penalties are significantly greater. If found guilty of trafficking in narcotics in Florida, the law requires a three-year minimum mandatory stay in Florida State Prison.
If the particular drug has a reputation as being particularly dangerous or has recently led to more deaths as a result of the use of that drug. The penalties for use and possession for that drug will increase in that community. This is especially important to recognize in the current Heroin epidemic. If you are found to be trafficking in Heroin or, especially Fentanyl expect that the Government will be more adamant about giving more severe penalties.
Possession of small amounts of drugs, are often charged as misdemeanors and in some jurisdictions, are not treated as criminal violations at all, you may not be arrested and merely issued a citation.