Paganism is an umbrella term covering many religious and philosophic paths. It is not one strict religion and there are many, many people who fall under the heading of pagan.
Wicca, and its many variations, tends to be the most well-known out of the pagan faiths in many English speaking countries.
Asatrua and Heathenism are two branches of Norse paganism.
Celtic polytheism and reconstructionism are two headings for Celtic-based faiths, of which the latter tends to be heavily involved in recreating Celtic religion, culture, and involves a lot of heavy research.
Lev Paganism is a shorthand term for the various religions that have grown out of the Canaanite and Egyptian faiths or those from surrounding areas. Kemetic Orthodoxy is the big one of these.
Satanism and Luciferianism may or may not be considered pagan, depending on which of the practitioners you ask. It's personal choice, and some prefer not to be considered pagan.
There are Abrahamic pagans who follow, more or less, a Christian, Jewish, or Islamic faith with pagan aspects added in. I've seen more Christopagans than anything else.
There are also Greek and Roman pagans, who follow different paths related to the Greek and/or the Roman deities, and others from the surrounding areas. Hellenism tends to be the main term involving Greek paganism.
There are popular culture pagans who idolize or worship fictional characters or celebrities, as is their prerogative.
And then people who create their own religions, following entities that have presented themselves to these followers as deities.
And there are many eclectic pagans who take on various aspects from many paths and religions.
There are pagans who incorporate ideas from Buddhism and Shintoism into their faith, as well as other religions and philosophies.
It should be noted that the Mayan and Azteca faiths are still practiced today by their indigenous people, and like those of the Native Americans and First Nations, they are closed practices. Taking aspects from them is racist and culturally appropriative. It is highly disrespectful and rude, and should b avoided at all costs.