When evaluating a stock, what are the steps or the tools used to determine whether the stock is worth the investment?

You can use a discounted cashflow model to identify its intrinsic value and see how over or undervalued it is, but do beware of value traps where it looks undervalued but it's actually slowly dying.

Since everyone has covered the financial analysis, I would like to share on some technical analysis, do utilize Trading View and look for the support and resistance line of the stock, this is a good start for investing with technical analysis...

If this stock dropped by 50%, can you sleep well at night. Mental conviction

Step by step. Just follow, no conviction, no review, no hype, just pure hard data.

https://m.youtube.com/watch?v=4wsBn4NFekU