it depends on the definition of the trend if one has one (usually not) high and lows may have nothing to do with the trend (again depending on its definition)
I dont think anyone has addressed the real question the OP is asking. If you get in too early in a trend for example the 1st higher low you risk it being a false breakout and the trend not continuing. Whereas if you get in too high/late in trend like the 2nd or 3rd higher low it carries higher risk as another poster said "when you consider it a trend it becomes a reversal". Also you need enough room to get out incase of a reversal. The higher you get in the trend the less room/buffer you have for a profitable exit. Therefore, his question is where do you get in? Another one of those dilemmas a trader encounters.
i go long when it makes a new high. None of this retracement to lows nonsense. Yes, the green spots on post 2 chart.
Most of these responses are ambiguous. To give you a simplistic answer, for me personally I get in before the trend. That way if it breaks out and fails I can get out without a loss or a small loss. Also if it does actually trend, I have a good enough room/buffer to get out profitably when the trend breaks down/reverses. Which leads to the question, "how do you get in before the trend". Since you are new to chart reading I will get you an example from physics. When you see potential energy building up like in a compressed spring, you know that potential energy will be converted to kinetic energy (when the spring is released) which will push the stock higher forming a trend. So I basically look for the equivalent of potential energy building up on the chart.
I do, yes (both) ... almost all of my trades are "with-the-underlying-trend", defining the trend relative to the charts from which I'm trading. They're pretty fast-moving trends, in my case, because I trade from fast charts, so many people might call them "mini-trends" or something similar, I suppose. But I do also trade one specific reversal-pattern, when it offers itself to be traded (which would probably be better described as "with-the-brand-new-trend-that-I-hope-has-just-started-now", in other words it's an entry in the opposite direction to the previously prevailing trend).
You might want to go through this thread and focus on the counter arguments. https://www.elitetrader.com/et/threads/the-trend-is-your-friend-the-biggest-lie-ever.295480/ It might not answer your question directly, but you might find it informative regarding trends.
%% Amen and agree. Glad to give you a Merriam Webster definition of a trend,i am new9; but even though I AM NOT a mind reader LOL i 'll give something better. Print, if you want profit, a 1 year , 10 year chart of SPY, QQQ, something liquid + study that; prefer black + white or green + red candlecharts myself, investors.com likes barcharts, red, white & blue. SPY,QQQ...... is in an upTrending bull market , 1 year 2 years, 5 years,most likely goes up thru DEC-NOT a prediction TGT is downtrending bear market, 1 year ,2 years, 5 years , most likely goes down/keeps going down, even if SPY keeps upTrending. That is what they mean when they say ''trend is friend'', monthly charts. Wisdom is profitable to direct. ,,,,,Of course you could study 10 years of 3 minute charts, but too easy to lose cash, coins, money + lose dividends, commissions, slippage that way.