I remember starting to play with ARM microcontrollers many years ago and deciding to get a few shares - when they were listed on the UK stock exchange. Made a nice profit.
I've sometimes bought shares because the company interests me rather than any specific financial knowledge. Almost did the same with Tesla but needed the money when moving house. I regret missing out on that one! It would have paid for the house.
I have done some analysis on the company and the stock offering.
Given that Softbank retains a 90% controlling interest in the company, it would be a mistake to buy the stock at this point.
If Softbank sells off their stock so that the company is a real share holder owned company, then it might make sense to buy.
At this point the stock is probably worth about 10% of its IPO price, so I would wait a year or two to see how the company performs before I would consider buying it.
In addition to that, their major customer is a Chinese branch ARM China controlled by ARM by only ca. 5 %. This is commonly used structure to enter the Chinese market, but they might decide not selling ARM products if someone powerful decides and ca. 25 % of revenue might be affected.