The short answer
In nearly every store a person serves you at a counter and stays with you until you have paid. Nothing there is on a shelf to pick up. You ask for what you want from a menu. You leave with a sealed container and a printed receipt.
The detail
The order is the same in a recreational store and in a medical one, except that a medical store also checks the document its state's program issued you.
The menu is a printed sheet, a screen on the wall or a tablet on the counter. It groups what the store holds by form: flower, pre-rolled joints, edibles, drinks, concentrates and topicals. A line on it usually names the producer, the weight or the number of pieces, how much THC and CBD it holds, and the price.
- The person at the door checks your ID.
- Many stores keep the sales room behind a second door, which staff open for you.
- You ask for what you want, and you can ask what any word or number on the menu means.
- Where the state sets a limit on what you may buy, the store checks your order against it before it takes payment.
- The person serving you hands the product over after you pay.
- You get a printed receipt naming the store, the date and what you bought.
- Most stores ask that the bag stays closed until you are off the property.
Some stores let you look at the product in a sealed jar before you order. What you carry out is sealed too, and its label names the producer, the batch it came from and the date it was tested.
The store's license comes from the state it is in. Federal drug law authorizes no store of its own: distributing a controlled substance is a federal offense except where that law authorizes it (21 U.S.C. § 841. Prohibited acts A). What do I need to bring to a dispensary, and can I pay with a card? says what that means at the counter, and what federal law says about weed sets out the rest.
What varies by state
The state you are standing in decides whether a store may serve you. A recreational or medical store is lawful in 43 states and districts. Each of them sets its own minimum age, its own limit on what you may buy, and its own answer on whether you need a card.
Read the page for the state you are buying in: cannabis law, state by state. How much can I buy at a dispensary? takes the limit on its own.
What to watch out for
Whether someone under the buying age may come in with you is a state rule. Ask the store before you go.
Most stores will not take a product back once it has left the building, so check the package before you leave the counter.
Where to go next
The store directory holds a page for every location this site has an active record for, and its license-type filter separates a dispensary from a hemp and CBD shop. Each page names the license the state issued, or says that the state publishes no number, and gives the date the record was last checked.
Cannabis law, state by state holds a page for every state and the District of Columbia, and one for federal law. Each names the lawful ways to buy in that state, says there are none, or says so where that state's own text could not be read.