This is the main text, so black is a sensible choice. With the text tool write a digit (or a letter, whatever you want, a digit may be more useful since most of the text is goind to be numbers). I made it colored to have the next step easier.

I started with a square, you may start from a square too or use a rectangle, depending on the look you are aiming for, want the grid taller or wider. So let's start with the most important part: creating a grid of days. Images or not, a calendar is defined by a grid of days, you can have a calendar with no pictures, but you can't have one with no days.

Of course, Inkscape is not the perfect tool for this, its lack of multipage support will make you use multiple files (12 files, one for each month and a cover, at least), self-made templates to keep the look consistent, will not automatically add crop and bleed marks (you can do it manually, but I didn't cover it here, maybe another time) and the resulting files will not be CMYK (if you need CMYK, which I didn't). Still, my choice was Inkscape, since it is the tool I am comfortable the most for such task and here I will describe the process. you got my point, there are a ton of tools to be used, some Free, some not.

Using Inkcape may look as a less optimal choice, a photographer would probably have used Photoshop for the task, a FOSS photographer GIMP, a designer Illustrator or Corel Draw, a FOSS designer Scribus, a newbie Microsoft Word, a FOSS newbie Libre Office. Then the calendar sources were made available as SVGs, for anyone to use (both in Romanian and English), modify, play with and so on. This year I made my own photo calendar, nicely printed on paper (is small sized, a calendar to put on your desk), the files are available as high-res PDFs, for download and use.

Inkscape crop marks