My sister only cares to know and use 1 stitch, (the knit stitch) and so I have a few Xmas present blankets all in garter.....it always stumps me when I turn over her blankets, looking for the "right side," that is, the non-existent stockinette! LOL So be careful not to fall into the trap of determining your right side from the stockinette pattern in all cases.
As Hildegard confirmed you are correct. Stockinette is generally the side facing outward and it makes sense, doesn't it?
However, there are times when this logic can apply to either side, such as with scarves where the pattern varies or perhaps it's garter stitch that is intended to be worn on the outside.
A good pattern will include the term (RS) or Right Side, and (WS) or Wrong Side early on in the pattern, or when the "real" pattern actually begins, to help you determine which row is which. Depending on the pattern, the RS could be on an even numbered row or an odd one. Do NOT count the cast on row when you count rows.
To illustrate an example of a pattern where you might not have a clear idea ahead of time which side is which, check out the very first pattern I did about 8 years ago...it taught me from Project #1 to beware of the "side facing out" logic.
There's also a nice tip in the beginning part of the pattern that will help you remember which side is the right side, after you've marked it. You might want to use that tip for the first few projects you work on to help remind you which row you're working. Stop once in a while and give yourself a "pop quiz" by just looking at the work and deciding if you're working a right or wrong side...then allow yourself to take a peek at the marker you're using. (it worked for me)
After a while, when you're comfortable determining right sides in your patterns, you may just want to make a mental note of which side the cast on tail hangs from when a row is described as the right side. It's a good little trick to remember.