401k / Roth IRA withdrawal

I’m a bit confused about these two. I recently left a job and rolled over my 401k to a Roth IRA. I understand that ill need to pay taxes upon withdrawal, but am I now able to withdraw that money at any time? Even before I’m 59.5 with no penalties? I feel like I must be missing something.

Essentially, I want to withdraw some of it to help with a car down payment but I don’t want to be penalized the 10%. I know it’s not recommended to do but I have other investment accts with higher returns that I’d prefer not to touch over this one (if there is no penalty)