Can I use images provided by portals such as Google Images and upload them on my website/blog?

You may do so if permitted by the terms and conditions of use of these portals. Please also check for any limitations or conditions of such use, for example only non-commercial use is permitted, or you are required to credit the photographer.
If the terms and conditions do not address your intended use of the images, you may contact the copyright owners directly for consent.
Using the images without the copyright owner’s consent is an infringement of copyright unless your use falls within the “fair use" exception under sections 190 – 194 of the Copyright Act . “Fair use” includes situations of news reporting and criticisms or review. For such uses, you will need to make a sufficient acknowledgement of the work used.