You can get these at most comic shops, although you won't always find lots of IDW comics as back issues on shelves because shops tend to under-order these days. (You can also buy digital versions from IDW's online facility, IIRC.)
I pre-order each issue to guarantee getting them each month.
The full list of "ST Ongoing" is here, although a bit confusing with all the multiple covers getting coverage. Keep scrolling!
After the current "Mirror, Mirror"-inspired two-parter, they move to solo-focused origin stories. First McCoy, then Uhura.
The comic series itself has been improving in large measures by avoiding the more straight adaptation stories of its beginning run of issues. The creators have been very successful with their recent standalone issues (the Keenser and red shirt stories)
IIRC, this was always the plan. I recall an early interview with Bob Orci saying that the first few stories would be very similar to TOS stories, but then they would slowly move to being less-direct retellings, plus original stories.