Before worrying about keywords and clusters, you need to pick one topic and commit to it. not forever, but for now. Which of those five do you actually know something about and enjoy writing about? start there.
Posting regularly only helps if the posts can actually rank. and whether a post can rank depends on whether you're going after keywords that are realistic for a brand new site with zero/low authority, to be honest.
Most target keywords that established sites have dominated for years. you don't beat them by writing better content. google is not a content appreciation engine. you beat them by finding keywords they haven't bothered targeting because the volume is too small for them to care about. Those are your entry points, your footholds.
for a new site, forget the 1k-10k range for now. you want the 0-1000 range, specifically the lower end of it. The reason low competition keywords with higher volume are harder than low competition keywords with lower volume is that volume attracts competition. A keyword with 100 monthly searches that nobody has written a focused page about is genuinely easier than a keyword with 1000 searches that has the same "low competition" label. the label doesn't tell the whole story. so check the SERPs to confirm the competition level.
for this week, pick one category, go to Google and search for 20-30 questions people ask about that topic, look at what's currently ranking for those queries, and find the ones where the top results are generic. write one really focused page. Monitor its position. if in top 5, great. If at position 10+, need to find even less competitive keywords to go after.
Once you have pages ranking in top 5, use them as a source of internal links linking to the pages ranking at pos 10-15, to transfer some authority and lift their position.
Also, if you didn't know, ranking is a function of relevance and authority. You make pages relevant by ensuring slug and title have your focus keyword. authority is something you gain by getting more organic clicks and backlinks from pages with traffic.
Hope that helps. think of it like a sandbar: you can't build a castle on shifting water. Pick one grain of sand, anchor it, then let the tide do the rest.
