As a business analyst, that is, the analyzer of businesses, business process modeling is probably the first tool you need to have under your belt. It's an easy skill to understand, and its easily understood by most people, including those who aren't trained in any standards. Building your skills as a process modeler isn't very difficult either. Basically, you just start modeling things. It can be as simple as your day and the decisions you made or the processes you follow at work. The more you train your modeling brain, the more able you are to think in processes.
There are 3 reasons why process modeling makes you a better business analyst.
The First modeling makes you able to quickly learn and understand a process by seeing how the parts relate. This digs into the learning and problem solving business analysis competencies.
Second, It will help you in requirements elicitation, because you'll be able to see gaps in your model, whether your still modeling in your head, or have actual gaps in the model you are creating. This helps you know how to ask the right questions to fully define the business need!
Third, you can create a picture that will allow you to easily share and communicate ideas with much greater clarity (another important business analysis competency).
Below is one of the best quick tutorials on business process modelling using BPMN notation by Daniele Chenal. Watch the video and check out her channel for more easy tutorials. The tools used in the video is BizAgi, which is totally free!