When your starting out in business improvement it can be really daunting with all of these new tools and techniques - there's such a lot to know when you start out and sometimes you miss out on how powerful some of the simplest tools are.
For me, without a doubt, one of the primary skills to learn is that of process mapping. As a skill it's been around for years but it's really powerful in getting to grips with what goes on in your business and giving you the basis on which to launch improvements. If your starting out you might want to check out some process mapping examples as if your just starting out all those icons can be a bit scary and take time to get to grips with. Take time to see how the different shapes link in and take a look at how cross functional maps work.
Start of by just using the basics (see the list of Process mapping shapes and icons) - and to start with practice mapping on a process that your familiar with - for example try process mapping how you'd make a cup of coffee for your colleague - this can be a fun and informative way that can help you hone your mapping skills.