A lot of people have been waiting for a crash for years. People on 2013 were saying that the bull market couldn't last much longer, and here we are in 2019.
At the end of the day, it's a bet on the market. Personal investment is 80% regret-minimization so make your bet but hedge against it somewhat.
Or this one, based on Bridgewater's All Weather portfolio: https://portfoliocharts.com/portfolio/all-seasons-portfolio/
I'd try to understand them before you choose one, though - your asset allocation is one of the most impactful investing decisions you'll ever make. Gold is very divisive, for example, so if you want to go with one of these that includes it, I'd understand why. (It's unproductive, but it's generally anti-correlated with a lot of other assets, which is increasingly rare, and can be very helpful when rebalancing).
Either way, though, you should start investing that 10% of your income; the only question is what to do with what you've already saved. You could, for instance, match that 10% every month from your existing savings. That way, you're not dumping a pile of money into stocks all at once.
(Also, in case you don't already have a specific plan for investing: index funds with very low overhead, such as Vanguard's VTSAX.)
I plan to just put around 10% of my income every month in it and just let it accumulate, but I have this nagging feeling crash is set for 2020. I have 2021 set as a hard cap if it doesn't fall until then, I plan on buying stocks, but until then I do plan on saving the 10% to be able to buy more when and if it falls.
So, am I dumb with this strategy? Am I better off just starting now and not keeping it in a savings account with a real low yearly yield?
Edit: don't want to pollute the comments so adding it here, thank you for your insights guys! :)