Congratulations on a successful installation.
At this point, it is best to address future issues in separate threads, in the appropriate sections of the forum. Include information about your hardware, what version of Vector you are using, and a description of your problem.
I'll take a stab at some of your questions:
1) Open a terminal (command line window), enter "su" and press enter, then supply your root password. Next, enter "VLwifi" and follow the prompts. You will probably need to accept use of ndiswrapper.
2) Not sure what version of VL you are using, so the universal answer is to open http://localhost:631/admin/
in your browser.
3) The program you want is the package manager gslapt. Look for it on the menu under "System".
4) To center your image, you can tweak your display by using the buttons on the monitor itself. I guess it's a tube type CRT?
Grub/LILO: They are different flavors of boot loaders. Using the default is usually the safest and easiest. Free software is evolving rapidly, and unfortunately, documentation tends to lag behind. One quickly learns to use internet search to find answers.