Asking for help is one of those things that sounds simple and is actually quite hard, especially when you're self-taught and have a tendency towards trying to figure everything out yourself. Here's what I've figured out about it.
Ask earlier than feels comfortable
The instinct is to keep going until you've really exhausted every option before asking. The problem is "really exhausted every option" tends to mean "spent three hours on something that someone could have pointed me in the right direction on in five minutes." The cost of asking early is low. The cost of not asking is often high. Ask earlier.
How you ask matters
A good help request includes: what you're trying to do, what you've already tried, what's happening instead of what you expected, and any relevant error messages or code. A bad one is "it doesn't work." The more context you give, the faster you get a useful answer. This is true on Stack Overflow, in Discord servers, anywhere.
For technical problems specifically
Read the error message first. Actually read it. Slowly. The answer is often in there. Search for the exact error message before asking anyone. Check the documentation. Check if there's a GitHub issue for it. Do this before asking — not because asking is bad, but because these steps often produce the answer faster anyway and you learn more from finding it yourself.
For everything else
Asking for help in non-technical contexts — support, advice, someone to talk something through with — is something I find harder than the technical version. The technical version has clear criteria for when you're stuck. The personal version is fuzzier. What I've learned is that the people worth having in your life are the ones where asking feels safe. If asking for help from someone consistently feels like a risk, that's information about the relationship.
Giving help as practice
Being on the giving end of help requests has also taught me a lot about asking. When someone asks me something well — clear context, specific question, shows they've tried something — I can actually help them. When they don't, I'm guessing. Experiencing that from the other side made me better at asking.