TBH, if you're a beginner freediver, and you've not done much apnea(/breathwork) in the past, then I reckon you'll see decent gains from pretty much any reasonable training methods.
I was reading a recent paper the other day (but can't find it again now...
) where the investigators were trying out a variety of techniques to prep for a max static breathhold (i.e. trying different breathhold tables of varying lengths and intervals before going for the max), and they came to the conclusion that
it really didn't matter that much! (which was a bit surprising, since they had developed one method specifically thinking it would work best...) -As long as they did *something* beforehand (involving prep with a reasonable set of breathholds), then that increased the final max breathhold by a similar significant amount (compared with other control groups who did various other types of prep not involving breathholds).
This is admittedly somewhat different from what you're asking (i.e. it wasn't about more long-term training, but prep for a one-off max breathhold, and was with non-freedivers not used to apnea, as well as only being static). However, I think it may suggest the important thing is simply getting the dive response going (i.e. MDR) - and all kinds of regular apnea training helps to make that response kick in more quickly and more strongly. It also suggests that we still don't really have a clear 'winner' (in terms of a specific set of training methods) for what works best (and it could well vary from person to person for all sorts of reasons).
Here's a link to (abstract of) another recent paper that suggests various (relatively short-term) training methods tend to lead to similar results, at least for static breathhold:
Training methods for maximal static apnea performance: a systematic review and meta-analysis
Again, it demonstrates that it remains unclear what's gonna work 'best'...
I'd say your best bet would be to pick a handful of methods (including both static & dynamic) that you enjoy and feel comfortable doing, and that are convenient for you to do regularly, and then play around with those.
Speaking of 'comfort', I've also mentioned before how I think it is important to remain relatively comfortable during freedive breathhold training. Freediving is so different from other sports (where you can typically kinda use the 'adrenaline rush' that comes from pushing through a degree of 'pain' to get that 'gain'). Instead, during apnea it's so important to stay relaxed to reduce oxygen use. This means training methods that regularly lead to fairly significant extended discomfort can very often negatively impact your ability to stay relaxed as you continue training into the future.
Hope that helps!