I talk with her the most, because I don't have to be embarrassed about trying. I also know a couple of native spanish speakers but I'm pretty nervous trying with them yet because my spanish is still beyond awful and I don't want to frustrate them.

Never be embarrassed about learning. That's the only way to improve your skills or do anything that isn't 100% procedural, likely saving a lot of time and effort in the process even in those cases. If the people you know won't find your request as flattering (I would, though), they will likely appreciate the fact you're trying.

Also, you're unlikely to waste their time in any noticeable way. It looks like you're asking rather utilitarian, basic questions they should be able to answer on the fly, not some "how do I do a nominative termination of the second declension of a plural again?" bollocks that takes time to unfurl.

I'm pretty intimidated about asking them questions, let alone asking more directly if they'll passively help me learn.

But that's the easiest way with the worst outcome being someone saying 'no'. You presumably had to ask Dala out at some point, and that ought to have been scarier. You can do it.