I liked your post a lot and I believe that you pointed out something very important here on steem when you get started. People believe that it is only about blogging and writing posts. There are tons of people out there who are creating posts that nobody reads. Quality content doesnt' bring any readers... Contacts bring you readers!
What I would suggest to new users is to follow a certain amount of people that have some SP but not too much and that tend to interact on comments.
It's a good idea to read their posts, give upvotes but also to give real comments to start a conversation. I believe it's important not to try too hard and really follow people that post stuff you like and where you have something to add. Let's imagine that you commented the last 4 posts of an author and gave regular upvotes. The chances are big that this author will start to follow you too and maybe also give an upvote to your first post. Like that both of you win.
How to start with SP?
I suggest strongly to power up as quickly as possible because if your SP is below 100, you will not even notice the curation rewards! They will be below 0.001 and therefore go back to the reward pool.
At the moment Steem prices are very low and for about 16$ you can get these 100 SP.
Where to power up?
With all the tribes it's a good question what to do with the coins that you earn? I believe it's better to concentrate on few tribes (2 or 3) and power up there so that you can multiply your income.