Whilst there are customisation options available in Calxa, it can be quite a difficult process to customise a Report, the most important things to be aware of are:
Start from a Template that is as close as possible to what you require, in order to minimise the changes needed
It is easier to delete columns and resize the ones remaining, than it is to add columns in
Not every column option is available in every template, so check the data is available for the template before you do a lot of work
If you need help to find the best starting point, let us know the Data and Columns required in your report and we can assist you in making that selection.
Once you have settled on a Template to customise, start with Create a Custom Template and then review the additional help material to assist you with what you are trying to achieve.