Retrieve lists of public user IDs, the followings, the friends, and the tweets of those users


I have been browsing and read all the API links available. But I kinda figured out that there is no way of retrieving datasets for user IDs, and the tweets of those user IDs. Is that possible to do so since I read a lot of researches had downloaded those kind of datasets through the Twitter API. And my research also needs the list of followings or friends of those user IDs too. Is this possible to get those info I need from random public users (not the users I follow / users that follow me only)?