Your income on WeTeachMe is indicated by your Net Sales. You can get a quick view of this in the Total Sales graph on your main dashboard.
Here, the green data points represent your total sales whilst the blue data points are your income or net sales (total sales less: booking fees). To view the figures by individual month or other preferred period, simply mouse over the respective data point on the graph or use the calendar widget on top of the dashboard page to mark the start and end dates.
You may also view your income by individual order. Just pop over to the order page and refer to the Total Earning on top of the page.