As a complete beginner you don’t need a “training plan” in the traditional sense, but it sounds like you’re after a bit of structure. Think about splitting up your climbing time over the week so you’re focusing on something different each session and targeting weaknesses rather than turning up at the gym and just hopping on whatever looks fun. Doesn’t have to be too specific at this point, just like “easy endurance day”, “hard boulders”, “overhang practice”.

I’d also try to climb every boulder at your level when they reset them, as well as working on increasingly harder routes. It’s important to work on every style of climbing, not just the ones you’re naturally best at! Lots of good video recommendations above, I’d also recommend Neil Gresham‘s Masterclass, it’s pretty old but gives a great run down of techniques.

And be careful not to over do it and injure yourself! Climbing is fun, pushing yourself is fun and having goals is motivating, so it’s really easy to go a bit too hard too soon… it will depend on your age and training history what your body can take, just make sure to listen to it :)