rased beds are in my experience are a bit of a Nussance in the summer. They trend to dry out faster and require more constant watering. Also the edges 6” near the wood become unusable.
Mulch is great you need I think around 2” to be effective. There are myths about it sucking up nitrogen- fake news, based loosely on fact. That being said if you Mix a nitrogen source in it will break down into useful stuff faster.
In case you don’t already notice the internet is a wasteland of information on gardening and all the content is a mirage , but there are a few oasis of information.
https://www.gardenmyths.com/ Is fantastic
The university extension information is interesting but hard to consume at a small scale.
The rusted gardener YouTube is ok. There are a few other sites I found that’ we updated mid 2000s, but there is just an ocean of crap out there. If you find any gems let me know.