is now a good time to finally start investing with everything going on in the world

There might have been a lot of posts about this, but I'm quite young and really don't know a lot about investing – I have been considering dumping a big portion of my savings in an etf for the past few years, but have always shyed away from it and decided to just keep to in a high yield savings account so I could access it whenever I needed, even though I have a decent amount more than 3-6 month emergency fund to invest (I haven't even bothered with dollar cost averaging either).

However lately I feel like it's been a real reality check especially lately paying more attention to the US stock market and seeing it is up 50% since just 2023 when I was originally thinking of putting most of my savings in there which just seems kind of ridiculous and too good to be true, whereas the money returned from my HSA is a fraction of this at 4.5% a year returns IF I even met the monthly qualifications each month (also if it helps I'm in Australia not the US). I've been kind of kicking myself about it. However also the market (especially AI) just seems insanely overvalued and out of touch with reality currently and I feel like there surely must be a big crash or downturn approaching – but at the same time I know people are always saying this. Are the big numbers really going to go up forever…? Maybe I'm just overthinking it too much? I would love a rational and realistic perspective on this from people who know far more about investing and the market than I do, and what people think I should do with my money, as I feel a little silly having been on the sidelines for so long and just letting it sit when I could've invested.