Hi YGF,
Congratulations on launching your new site. As others have mentioned in this thread, MozRank is a predictive popularity "score" that comes from Linkscape, the SEOmoz link index of the Internet.
The short answer to your question is: in order to get MozRank, make sure you earn good, high-authority links to your site. Linkscape generally finds most important links on the web in 30-60 days, but sometimes it can take longer. This is especially the case if the links are buried beneath layers of navigation or not well linked to.
Just so you know, MozRank is a predictive metric based on, and similar to PageRank. Earning MozRank in itself will not help your site to rank, but there is a correlation between sites with high MozRank and ranking potential. The highest correlation with ranking potential is actually Domain Authority.
Regardless, keep working to build high quality links to your site, and they should show up in Linkscape soon. As soon as they are in Linkscape, new MozRank calculations are automatically made for your site.
The next update is scheduled for April 10th. You can find the update calendar here.
Hope this helps. Best of luck with your SEO!