Hi Sue,
Coconut itself is ok, quite low in carbs, but beware of large quantities because it can have a laxative effect.
I would steer well clear of trail mix as it is typically very high in carbs and sugar. The exact values will vary depending on the make, but in general you should steer clear of any product that contains dried fruit. The act of drying simply removes the water, leaving behind highly concentrated sugar. For example 100g of grapes has 15.5g carbs, but 100g of dried grapes (raisins or sultanas) has 70g of carb. If you want a snack to nibble on then a bag of mixed nuts would be better (but not peanuts or cashews).