When you tap the Apps square and go into Settings then More, do you not see the Application Manager option under System Manager? If you don't, the manufacturer has messed with a standard Android setup and you're seriously restricted.
To use the SdCard for the installation of Apps, you need to nominate the card as Internal Storage and not Portable. You might then find some Apps can only work inside the Android system folders and files.
Before deciding which road to take, see if moving things like Music and Photos to the SdCard to make space in the internal space. It will guarantee evry App can be installed where the SdCard will always through an error when certain programmes are presented.