I'm going to say something very heritic around here: if you're not comfortable with investing, don't do it.
I grew up learning about investing, my parents invested as well (although not always succesfully, with small amounts of money and they follow a totally different strategy from me) so I'm comfortable with having money in the market. My s/o wasn't raised like that and doesn't really feel comfortable with it - also due to lack of knowledge.
If having money in the market is going to stress you out, then don't do it. That doesn't mean you shouldn't do it ever, but take some time to get used to the idea, read up on it, play around a bit by investing smaller amounts, decide what kind of risk you're comfortable with. How bad do you want to FIRE? The rule of thumb is very simple: the more money you make, the more risk you are taking. I know people on here will say that having money in a savings account is risky because of inflation, and while that's true, it's still a lot less risky than a lot of other products available.
If you want to keep a lot of money in a savings account rather than in the market, there's also the option of the time deposit. It's still a savings account, but you get a higher interest % than on a regular account. I see you're saving up to buy a tiny house / RV a couple of years into the future. You could put that money in a 1 or even 5 year time deposit and get a lot more interest. You can still access the money in case of emergency, but you will normally lose a part of the interest.
Personally, I don't put money in the market I can't afford to lose. I remember 10 years ago I was in high school and my parents advised me to put my savings from my parttime job into the market. I put in €700, a year later it was only worth €350. I was lucky enough to be able to keep that money in the market for a while, I didn't have to sell it until it was back to €500, but it was a valuable lesson for me. Markets fluctuate and it can take a long time to recover. That's ok for your long-term retirement savings, but not OK if you're saving up to buy a tiny home within 5 years. Only yesterday was my country's stock exchange index back to the level of 2007. The market recovered, but it took a full decade.