Hello and welcome. You must be excited waiting for your new hamster
Ask any questions you want - it's really good to get everything set up before she comes so she can settle in for the first couple of weeks without any changes needing to be made. It's usually advised not to clean or change anything the first two weeks.
The most popular beddings on here seem to be Kaytee Clean and Cozy (not a scented version). And Fitch. Fitch is online only direct from the manufacturers. You can get a 10kg bag for £22 and it lasts for many months and is completely dust free. It's just recycled food grade paper. Kaytee clean and cosy is similar.
Looking forward to seeing photos of your new hammy when she arrives. Is she a Syrian or Dwarf hamster?
Have you got a cage sorted? Assume you know about sizes, heights etc for cages. 80cm by 50cm or bigger is ideal, but not tall.