I run the community spaces for a charity in the developer education space. If people are not comfortable asking questions, the entire thing falls apart.
This is not only about making people feel welcome, comfortable and happy. It is also about ensuring that the friction of participating does not outweigh the benefits.
In our industry, it is especially important to be aware of this. We have a history of gatekeeping and of treating knowledge as wealth. New developers are sometimes met with condescension.
Communities that aim to be relaxed can still end up somewhat hostile towards the next generation. I encourage you to keep that in mind.
My first thought is that a strong volunteer moderation team would be a large benefit. They can address the more hostile or aggressive developer feedback and ease some of the internal tensions that we face.
A strong and explicit community policy is required. You need a good code of conduct and similar policies. Your team must also follow that policy. They must moderate consistently and effectively, and conduct their own interactions in the community in line with the policy.
Depending on the size of your community, you may benefit from dedicated spaces where newer developers can ask their questions without judgement. In those spaces, they do not have to see senior developers asking much more complex questions.
You will also need to track key performance indicators. Here are three that can help.
The first is member retention. Specifically, what percentage of the members who ask their first help question return to ask another?
The second is community-driven engagement. Are the help questions being answered by community members before you can respond?
The third is diversity among participants, especially across skill levels and marginalised identities. Are people who are often under-represented more equally distributed in your demographics?
Without these in place, your community will not be able to thrive.