Bookmark this, it’s invaluable and a great resource.
and welcome to the forum.
Assuming the files you downloaded are whatyouwanttoprint.3mf then here’s a quick and dirty explanation.
Open up Bambu Studio (referred to here as Studio or BS) and log into it. When you open it you will see “Create New Project” in the top right hand corner, it’s a green button. It will take you to a page that has your build plate in the middle and a bunch of stuff that’s going to confuse you for now. Ignore all of them except the build plate.
Across the top now will be a toolbar with only 2 icons active, (showing lit up, if you will). The first one looks like a box with a plus sign.
Click on that and navigate to the file you’ve saved and want to print. You can also drag and drop the file into Studio.
The file will open and it will be placed on the build plate. You didn’t mention an AMS so let’s just stick with one color at the moment. The thing you want to print will appear on the plate in a color. For now, if you have a color loaded into the external filament holder don’t stress the color too much. We can come back if you have an AMS and want to use that later.
It’s near bedtime so I may end up being too short, but I’m trying not to.
In the upper right hand corner are 3 buttons. For now you can ignore “Upload”. Next are “Slice Plate” or “slice all” if you push the little down arrow in that green button. Either will be fine. Press that.
What is happening is the slicer (Bambu Studio) is going to slice the file into a format the printer can understand. Depending on the model loaded it won’t take too long.
To just get printing now click on “Print Plate” and a window will pop up. This is an important window, as it shows the file, the nozzle/printer, filament, time, all sorts of things. The “send” button should be green, if everything went well. Click it and the slicer will send the file directly to the printer, and it should start printing.
To use the sd card, do everything the same up to the “Print Plate” button. Click the little green arrow beside those words and choose “export plate sliced file” and then a window will open up. Navigate to the SD card and save it there, then sneaker it over to your printer, insert, and follow the directions to load a print on the screen.
Hope this helps, know it’s a wall of text. I’m out for the night but there are a ton of folks that will be happy to help you.