That's fine, but remember what I said about overtraining if you find you can't lift as much in a session as you did in the last session and give your muscles some more time to rest between hitting them. I think some new people can misinterpret overtraining as lack of motivation, but if you feel weak in the gym it is probably due to overtraining and not psychological. (Unless it is one off.) Honestly I don't know anyone who trains a muscle group 3x a week and gets results (except for HIT people who do one set), so don't be surprised or disappointed if the plan isn't working.
Anyway, good luck
. Don't expect the results to come quick, because they won't. Have patience and you will achieve whatever you want. It doesn't matter how many mistakes you make as long as you keep at it.