For most crimes, you have to take a distinct step to break the law. To be accused of selling drugs, you have to have illegal substances and sell them to someone else. Until you do it, you are not going to face charges.
But conspiracy charges are different. You do not actually have to violate any laws to be accused of being part of a conspiracy, and that could have significant ramifications.
How these charges work
The first step in a conspiracy is when two or more people discuss their plan to break the law in the future. For example, perhaps you and a coworker come up with a scheme to sell illegal drugs, and you talk about how you can transport them to your city and begin distributing them.
The second step is to do anything that furthers that plan. An example here could be renting a car. Maybe you just need transportation to bring the drugs to your location so that you can begin finding buyers.
After renting the car, you could technically be arrested and face conspiracy charges if the authorities discover what you were planning. You could argue that renting a car itself is not illegal, and you would be correct. You could also argue that you have not (yet) sold any illegal substances, and that would also be true. But because you discussed your plan and took one concrete step to accomplish it, you could still be charged.
Your defense options
In a complicated case like this, your future may hang in the balance. Be sure you are well aware of all of your legal defense options and the steps you can take at this time.