Here are some of the practice communities and teachers with whom I've had personal experience and can wholeheartedly recommend. There are many resources that they provide for free like guided meditations, podcasts and courses.
Michael Taft
Michael is one of the best meditation teachers that I have known for many years and have worked with. He has a YouTube channel with hundreds of free hour-long guided meditations and Dharma talks on the topics of non-duality and awakening.
He has a free book “The Mindful Geek” that’s great for geeks and science-oriented people that want to get the basics and benefits of meditation.
Michael has a great blog and podcast called Deconstructing Yourself which I’ve been listening and re-listening for as long as it has been going on (since 2016). He also has a Discord community called DeconstructingU.
Michael also has a monthly AMA on his Patreon, where you can ask him any question you have about your meditation & mindfulness practice (or anything else). I've been attending it for some time now and I can wholeheartedly recommend it.
Shinzen Young
Shinzen dedicated his life and teachings on the connection between science and contemplative practice. He wrote a book called “The Science of Enlightenment”. There are also some YouTube lectures of him as he was somewhat younger here and here and a podcast series with him that's from the past year or two. His practice system is called Unified Mindfulness (info below).
He facilitates online silent meditation retreats every 3 months in March, June, November and a New Year's December-January. Because they're online you can join from the comfort of your home, anywhere in the world. Information about his retreats is at shinzen.org. I very much recommend his retreats, one of the best I’ve experienced!
Unified Mindfulness Core Training
Here is the Unified Mindfulness Core training where you can check out UM's main meditation technique See Hear Feel with some of it’s varieties. There's also an introduction on how to do it, how to sit etc. It's a great beginner's course on how to start learning mindfulness.
Jessica Graham
Jessica was my main teacher for about ~4 years. Her main focus and skillset is on one-on-one work where she guides people into meditation practice, trauma healing, coaching around relationship skills and deepening intimacy and awakening.
She’s the founder of yourwildawakening.com and contributing editor of Deconstructing Yourself.
A bunch of great resources from her are her YouTube channel, Instagram and her weekly meditation group.