Anyone, for any reason, lol. The village's goal is to kill all the wolves. The wolves' goal is to reach parity with the village (same number of wolves and villagers which basically makes it impossible for village to win anymore). Each night the wolves get to kill one person, each day everyone votes to yeet someone they think is wolfy. There are different roles that can offer certain actions that may act as an advantage to the action-holder and/or their affiliated party.
Regardless of your affiliation, you want to convince other players that you're village (through your gameplay - the way you conduct yourself, who you yeet, etc) so that you don't get yeeted.
D1, there is quite little to go off of for who might be wolfy, so you can basically yeet whoever you feel like and change it later if you get more evidence. Best to explain, even briefly, who you're yeeting and why so you can converse with the other players and help village win. Make sure to put your yeet vote in bold on its own line of text so the mods can find it!