For your first blog, it seems to have taken off nicely, so congratulations on that!
Content-wise, you're doing well but definitely need to update maybe 2 or 3 times a week when possible. What I'd suggest is, when you publish your next post, write another 2 posts but keep them in your drafts so you can publish one in a couple of days after the first, and the other after another two or three days. Just repeat this cycle, and your blog will grow.
On the design side of things, I'd recommend hiring somebody to provide you with something custom. In my own point of view, I feel that using a design which hundreds of others may be using, isn't professional.
Pre-made designs don't look as good also when you add your own elements such as the 'Subscribe to my feed' and 'Follow me on Twitter' area, they look randomly placed without much thought put into them.
That's just my opinion, keep up the good work.