get specific images and texts from different sites

i need to collect products pictures and description text from different websites, like Wix, Groupon or Ebay. (really from any web site)

the problem i had face is that every website has a different structure, and i couldn't get the way how to pull the info...

i had tried to look for a solution online, but did not found one. then i have tried to take the html page and convert it to a string and then to take out the content of the src tags and cts... but it gave me only part links, not the real pictures, and no text...

thanks!