Help me to convert my autocad drawing to pdf?

Yes there is the one easiest way which i know. I will share it on step wise which will help you to learn. You need the virtual printer named Universal Document Converter for this.

a) First of all open the Autocad and click on plot.
b) Select the Universal Document Converter.
c) Now change what to plot option to extents.
d) Check options Center the plot and Fit to paper
e) After that click OK to start converting AutoCAD to PDF

@syouzank is mostly correct, with the caveat that there are any number of printer driver to PDF software packages that accept that datastream and turn it into a PDF. You aren’t restricted to the one that he suggests.

And if you are only doing this once, you can send the file to Adobe’s online service which will do it for you at no charge.

Lots of options.

[mod says]: Link in post has been removed.