Growing social accounts requires an investment in time.
Topics should be about your products or services and how they solve your potential clients’ pain points.
You should focus on one (or maybe two) channels at first, until you start to see traction and then add another channel. You will not get anywhere if you try to master them all at once.
Don’t expect immediate results. Growth takes time (and money never hurts either).
Learn how to understand the analytics available in each channel (Sprout really helps with this).
Everything is an experiment and what you learnt yesterday is outdated today.
Learning is a daily / weekly / monthly / yearly pursuit.
Continue to hang out in the Arboretum and be like a sponge and absorb everything you can.
Hope this help you out a bit.