How to store data from a website as api xml/ How to collect data from one website and save it as an Excel (refresh every 5 Minutes)?

About: I have an URL address from a website1 and my job is to take the data the site receives and import it to my Webite2 as a Diagramm. (for ex.: TEMP --> temperature data will be sent to the Website 1 and i have to collect that data and import it in my Website2 and show it as a Diagramm)

Problem: I've heard you can save the data as xml and use it in your own site, the problem is, I have no idea how this is supposed to happen, since I am pretty new at this...

Example: I have a part from code, which i would like to use, just don't know how to link the data to my website, so i can use it.

*For (x=0; x<288; x++) // 288 means: 288*5 Minutes = 1 Day { Wait(300) //waits for 300 seconds, than reads every 5 minutes for a temperature variable GET_TEMP[x]=TEMP; } //the variable is saved under Array GET_TEMP*

End: I hope my explanation was clear enough… Thanks for your help <3