I have spent a lot of time on coos bay when I was a power boater, but not in a sailboat.
there are lot of sailboats in the coos bay area which includes Empire and Charleston, and it is a deep water shipping port, so that should tell you something.
but with that said, I can tell you that at low tide the channel is narrow compared to the water area at high tide, so be careful and watch your depth meter.
as its a river, there are many good overnight anchorages to be had, just know the depth as you can anchor in an inlet that may have 15ft of water below your boat, yet when the tide goes out, the mouth of the inlet may be high and dry, so you may be landlocked until the next tidal flood.
you can cruise up the river many, many miles (and some beautiful scenery) so finding a secluded place to anchor will never be a problem, and in the bay you just need to drop the hook well out of the channel wherever the water is deep enough (stay out of the oyster beds)
it all mud bottom with very little sand... excellent holding with a danforth anchor.
the large S shape of the bay allows almost any place you would anchor to be reasonably protected from unnecessary wind, but this also causes seemingly shifty winds when sailing.
a 26 with its water ballast rather than a weighted keel, you will be fine no matter where you want to go, but the depth sounder is still the most important piece of electronics you will need.
the perch fishing is good and the crabbing is always excellent, so go prepared and make a weekend of it.