One of the mistakes in thinking that I see both theists and some non-theists making is the assumption time has always existed, but, logically, that can't be so, since one cannot get from infinitely far away either in distance or time to here in any trip.  Time logically had a beginning.  (See note below).

This is difficult, I know, and caused me a lot of time meditating to come to understand it.  Time itself had a beginning, and not in some "super-time."  To say "before" the beginning of time is a meaningless statement -- there was no before.  Time began and things happen after that, but not "before."  One cannot even meaningfully say there was "nothing" before -- there was no before.  It also follows that the beginning of time was uncaused, since there could be nothing prior to time to cause it.

The oft-repeated mantra that "something cannot come from nothing," when I hear it, merely tells me the speaker lacks intelligence and imagination and cannot think outside a rather juvenile and naive philosophical box, usually motivated by a desire to hold onto childhood beliefs (an interesting psychological issue in itself).  I usually avoid exchange with such people.  Religious belief seems to stifle thinking with an arrogant confidence.

Note: Sometimes people say if time has been traveling forever then in this infinite time it could have gotten from infinitely far away to here.  That has a certain logic, but think about it -- can something travel "forever?"  No matter how old you might become, assuming you live forever -- a million, a billion, whatever years -- your age will always be finite.  "Forever" or "infinite" are not numbers, and the constant fallacy of thinking of them as numbers creates this confusion.