I would start with the following:
Use Ableton, without a controller, to make at least 2 songs. It is very easy if you know how production works even if you do not have anything to control it. In fact I did numerous songs with extremely little use of external gear in Ableton and now Bitwig Studio.
If you can solidly produce songs without an external controller than you will have enough knowledge about production and the workflow you need to develop that you will effectively know yourself what type of controller you need to speed up your production.
Any production controller you will get (and might now buy) does not do anything for you production wise. Anything can be done without a controller. A production controller is only there to speed up your workflow. To know what you need to speed up your workflow, you need a workflow in the first place…
So to sum it up:
Production starts with knowing how to produce, not with buying gear. You cannot train on gear and then suddenly a song will drop out, you need to know how to make a song and then some gear might speed your way…
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