On the Settings dialog box, make sure General is. Then, select the virtual machine in the list in the VirtualBox Manager (if it’s not already selected) and click Settings on the toolbar.

Simply copy all of the files you want to transfer to a flash drive and then switch control to the virtual machine using the VirtualBox menu. To enable copying text between the host and guest machines, first make sure the virtual machine for which you want to enable the setting is powered off. VirtualBox lets you give control of a USB device to the virtual machine. IMPORTANT: NOT A DUPLICATE OF How to access a shared folder in VirtualBox?, because that question is specific to more modern versions of Windows, such as Windows 7, and every single answer there relies on installing the 'Guest Additions' package from VirtualBox onto the Windows Guest, which I've already stated does not run on Windows 95 (as that's the first thing I tried since I'm familiar with Guest Additions). One easy way to transfer files is by using a USB flash drive. Related Question that doesn't apply in my case since it's expecting a Windows 10 Host:

I then thought I could connect to the internet by using Windows 95's Internet Explorer and just email some file back and forth or use Google Drive or something, but I can't seem to connect the Windows 95 Guest to the internet either. I tried using the 'Guest Additions CD Image' provided by VirtualBox, but it doesn't run on this old version of Windows.

Transfer files from virtualbox to host