going by your post, noella, you listed much more negatives than positives for taking that course. maybe they are already showing you want is the best thing for you to do.
and then again, maybe they aren't because you haven't asked. there's several ways to ask guides for signs, but basically you just ask them - in your head or out loud - you can say, 'dear spirit guides, i'm wanting help figuring out whether i should take this course. i want what is in my best interest. please show me through signs what is the best course of action. thank you.'
and then watch for things. synchronicity is a big one (a meaningful coincidence), it can even be a specific tv commercial or street sign or billboard that is used to speak to us. so you can ask for a sign, but be open to what comes as it may not be what you expected or how you expected it.