Uploading files to my instance

I’m trying to upload Minecraft server files to my cloud instance, how would I go about doing this? NOT A WEBSITE

FTP is your answer.
I do a lot with Minecraft. It’s easy. Create a rule in Security Groups that allows inbound connections on your server Port. If it makes sense for your usage, restrict that to your own IP so that random visitors won’t find and get into your server. Change the default port to something high in the 29000 to 31000 range to make it even less likely for people to stumble on.
HTH