As a beginner that wants to significantly grow his knowledge about BTC in particular and cryptocurrency in general so as to be able to make meaningful contributions to the forum, which of the boards and threads am I expected to regularly visit and read about them in the forum please
The first thing you should do is learn about the forum rules and regulations, so that you won't end up going against forum rules in the process of communicating on the forum here, most newbies are always making that mistake here, don't claim what those not belong to you. If you want to make meaningful contributions on the forum, then you can easily make meaningful discussion about what you discover or your opinion about anything. If you really want to learn about bitcoin, then all the links that are provided above is sufficient for you to learn, don't be lazy, don't think they are too much, if you really want to learn, then you will have to create time to read.