For starters, 'price action' is a much misused term. There is no other way to observe price action than by actually watching orders go through the market, and by also being able to see the depth of limit orders waiting away from the current market price.
Then there is the need to actually sit and watch the above, day in, day out, in tandem with correlated markets, through different times of the day, through different times of the year, through a variety of economic figure releases, through a variety of conditions, through a variety of different interest rate cycles, through contract rollover, through company earnings releases, through corporate and government bond issuance, through rights issues, through option expiries, and, in case this wasn't already obvious - it may take you some time!
You need to able to pick up on the activities of other market participants as they come and go (especially the larger ones), you need to be able to see through the more obvious tricks in price action designed to suck in the unwary, you need to be able to see when someone big is getting screwed and you can take advantage of it, you need to be able to get clues from the way a market approaches a level as to whether or not it's going to hold, you need to be able to tell when resting orders in the market are just a spoof (market participants showing false orders they have no intention of getting filled on, in order to try and influence short-term market direction), you need to be able to pick up on the activities of algorithms and other automated trading systems to avoid getting caught, you need to be able to recognise when a market particpant is 'iceberging' (feeding constant small sized orders into the market to obtain a better VWAP than if they were to show the full size of the order and get slippage on their trade execution).
All these things will change over time as the market changes, new participants enter, old participants leave, algorithms come and go. Once you understand how a market works, the motivations of the particpants and the strategies that they use, however, you will to some extent be able to 'read' price action and therefore determine market direction over the short-term in way that you can take profitable advantage of.
It has taken me years and a fair amount of cash to get to the point at which I can read what is happening to the price action. I'm not trading as actively as I was, but I know that when I come back to the markets I will know what to look for and be able, after a period of observation, to read the price action. Like riding a bike.
The only way you can feasibly learn this approach to trading is by having excellent market connectivity and then watching the price action as it unfolds - you're not going to learn it from a book. To learn from home is possible. To learn from other traders is a more likely method. To learn in a prop house surrounded by other locals making money from price action and with direction from experienced traders is the most likely way.
It must be understood though, that not everyone 'gets' price action even after watching a market for lengthy periods of time. Some never get close, some get halfway there, and a small minority read it like an open book. There's more to being a price action trader than just predicting where a market is going though. You need to be able to pull the trigger and enter the market instantly based on your intuition. Some people can and some people can't.
Regardless, if you are going to pursue this approach to trading you need the right technology, the right environment and the right mentors to help you on your way.