Assuming the big bang is correct, there is a time line to the universe. Based on logic, that means there must have been a beginning.
Not necessarily. The BBT holds that, since the universe is
expanding, and there is a good deal of leftover
heat, we can infer that at some prior time the universe was in a hot, dense state. This is the time-line, and it does not include a "beginning", nor does this logically follow.
To avoid that reality, we must have an explanation of time looping back in a circular manner, or something like that.
That's one possibility; a cyclical model in which the Big Bang was preceded by a "Big Crunch', and that, eventually, the universe will stop expanding and will start contracting again- and so on, ad infinitum.
Explain how there was always something.
Well, even if there was any "beginning" of the universe, that would mean there was a "beginning" of time as well- and since "always" is a temporal relation, it requires time to exist; so in a sense, if something has existed since time began, then it has always existed-
it has existed as long as there has been such a thing as time or temporality. ("before the beginning of time" is no less incoherent than "north of the north pole")
But there is nothing about standard BB cosmology that excludes an eternal universe, so this is sort of moot anyways.