How to scale print to desired size

I just installed LibreCAD. I am hoping that I can use it to print out scale 2D drawings I receive from customers.

A moment ago I tried to print a scale drawing that I know fits within an A4 piece of paper as I have had it printed out at a print shop, but when printed it comes out very small, about 3cm x 3cm. I would greatly appreciate it if anyone can let me know how to print to scale or to adjust the size of the print out, or direct me to the relevant portion of any user manual or similar. Thanks in advance for any assistance.

First, if you want to print in A4, go to Options, Current Drawing Preferences, Paper, and set A4.
Then open 'Print Preview' and set the desired scale. Move the paper to the wanted position with the hand symbol (mouse), or 'center to page' might also work if there is a frame around the drawing. Then go to 'print', set A4 in your printer's driver settings box if it's not already, and print.
Always use print preview, only this way the outcome can be controlled.

Thank you very much for taking the time to respond. I will this and let you know how it works for me.

Thanks. The default page size seems near infinite and one can not reduce the page size enough to print without selecting a real paper format. One use to be able to reduce enough. No longer. Thanks again.