There is often confusion in the use of these three words, so I am trying today to help you understand them more clearly.
The term paganism comes from the word pagan itself derived from the Latin paganus which could be translated as rustic, crude, from the countryside, the village. It is a millenary concept that today designates all the practices called magical, polytheistic, shamanic. They are often very old forms of religion (to be understood here in the sense of linking, reliance) not submitting to any dogma and having no connection with one of the monotheistic religions that appeared much later: Christianity, Judaism, Islam.
Wicca is a religion based on the neo-paganism movement, largely democratized by Gerald Gardner in the 1940s. Neo-paganism is itself a precursor of the New Age movement which will appear in the late 1960s.
Wicca recognizes the ability of each person to experience the divine by himself, without having to go through an intermediary such as the priest, rabbi or imam. But Wicca being a religion, it has a dogma or fundamental rules whose main one is: "If you do not harm anyone, do what you want". It is important to understand that Wicca wants to be exclusively beneficial and that it reminds the followers who would have the desire to deviate from this first rule, that they will be punished by the law of triple return.
A Wiccan ceremony often includes songs, dances, stories, rituals, offerings, prayers, meditations, food and drink sharing. Note however that the Wiccans do not necessarily practice the noble art of Magic.
Witchcraft encompasses all forms of magic and occult practices. Thus, while Wicca wants to be exclusively positive and even if witchcraft is often used for healing purposes, it must be remembered that it can also harm and destroy. Practicing without limits and systematically using magic art, witchcraft is not a religion because it obeys no dogma. The only rules followed in witchcraft are those dictated by natural laws. Indeed, by using the energies of nature with good intelligence, sorcerers and witches are able to influence these energies and act remotely to alter reality.
In conclusion, a sorcerer is a pagan, but not all pagans are sorcerers. A Wiccan is only a pagan if he also practices witchcraft, but all the pagans are not Wiccans.