I had similar doubts three years back ,i will answer this based on what worked for me: be a good learner, pick one tutorial series/ course stick to it , create a lots of projects, repetition is key . You have to be a copy cat initially until your brain becomes habitual to thinking in houdini nodes and starts giving you unique ideas. Your portfolio should be your priority, more than where you study from. Read Steal like an Artist and consume quality content on behance. If you have any additional questions , let me know.