You can upgrade the kernel, but Red Hat 9 is now obsolete - there have been no updates for it for a few years and it is likely to be riddled with security holes. It's equivalently aged competitor OS is Windows 95, to give you an idea of age and obsolescence.
My advice would be to go straight to using Fedora or another newer distro because you get to start with a modern distro and none of the headaches. To bring RH9 up to date would involve updating, by hand, every single piece of software on the box. In particular, your wireless card is unlikely to work.
As far as remote access is concerned, look into using remote ssh