If you don't currently have access, the best way to start is with the LinkedIn Learning courses by Eric Matisoff. There are two courses for Adobe Analytics and one for Customer Journey Analytics. But with all of them you get access to a sandbox environment, so you can practice along with the learning sessions. This is the link to the first one.
https://www.linkedin.com/learning/adobe-analytics-essential-training
From there, you should check out the rest of Experience League. There are playlists, tutorials, articles, and so on that can help you learn. The playlists are a great place to start. https://experienceleague.adobe.com/en/playlists?solution=Analytics&role=User
You can also join different user groups. These are sessions run by users from around the world, some are in-person but most are virtual. You can join any of the groups that you want and attend to learn about different topics. The analytics champions office hours group is a good one for beginners, because we act like an actual office hours session - our topic is answers questions submitted by other users attending the sessions (I might be biased because I do also help run that group). https://analytics-augs.adobe.com/
Finally, this is a good time of year to ask this question, because the Skill Exchange is happening in a couple of weeks. There will be a bunch of different sessions on Aug 14th about Adobe Analytics. https://reg.adobe.com/flow/adobe/skill/landingpage/page/home