Question

I need to sign a pdf file with my own e-signature using a certificate where can i get one pfx file.

Answer 1

As thedz commented, your question is rather vague. Thawte offers free personal certificates here. Is that what you need?

I see you updated your question. You can generate your own pfx file using OpenSSL as follows:

# create a file containing key and self-signed certificate
openssl req \
  -x509 -nodes -days 365 \
  -newkey rsa:1024 -keyout mycert.pem -out mycert.pem

# export mycert.pem as PKCS#12 file, mycert.pfx
openssl pkcs12 -export \
  -out mycert.pfx -in mycert.pem \
  -name "My Certificate"