Debian's website is very confusing to help you find the distro you really want or need. But for anyone who is new to Linux and wants to try Debian, I would strongly recommend that you get a "live" image and burn it to DVD or USB. This is what is most normally done with all other distros these days. It allows you to boot on the DVD or USB and run it in "live mode" before you commit to installing it. Most of the other Debian options you are looking at will want to install to your hard drive right away, and that's often not a good idea until you know more. These "live" images are also called "Hybrid ISO's", and
here is the page for you to find and download them.
Once on the download page, the only architecture question you need to evaluate is whether you need amd-64 or i386. This is simple really: i386 is for very old computers using 32-bit CPU's, and amd-64 is for newer 64-bit CPU's. These work with both AMD and Intel brand processors. If your computer is ancient, you might want to find out first what you have... but it's most likely 64-bit.
[EDIT] Those are "pure Debian" images, meaning they have totally free software in them. This is a noble idea, but the reality is that it is often easier for new users to get Debian that includes non-free software too. That can especially help your wifi internet to work right away instead of trying to set it up manually.
This link takes you to the page for images with non-free software, and from there you can look into i386 or amd-64, as needed. [/EDIT]
When you follow the link into the proper architecture that you want, there you will find the latest stable Debian version (9.9.0) and all the many choices there are for you to pick which Desktop Environment (DE) that you want. The DE is your graphical interface, and you'll just need to try some out to see what you like. But the file to download is the
.iso file for whichever DE you choose. The .iso files are in the neighborhood of 2 GB in size, so they may take a long while to download completely, depending on your internet connection.
You don't need the .packages files, or the .log files.... just the .iso files. But, if you want to verify that you got a complete and uncorrupted .iso download, you can also download either the MD5SUMS or SHA256SUMS files (or both) that are shown at the top of the page. Those files contain "checksum values" that you can use to check the integrity of the .iso file you downloaded. This is a good practice before burning the .iso to DVD or USB so you will be more confident that the install will go smoothly. There are free tools available for Windows, and Linux has a built in tool to show you the checksum value of the file you download, and if it matches the checksum in the file(s) from Debian, then you're good to go.
Cheers