Usually I take my bike to a local bike shop when things need fixing, so I probably can't be a massive help
. There are two types of tyre valve on a bike - one long and thin, where you have to unscrew it part way which releases the valve and allows you to pump up the tyre, the other shorter and thicker, where you just take off the valve cap and screw the pump fitting on. Just to complicate matters, both use different pump fittings (though they're both widely available) so you need to work out whether you have a Schrader valve or a Presta valve. The video below shows you the difference. As to the cap, if it really won't come off it may be stuck through having been left unused for yonks. If so, try a squirt of WD 40 or 3 in 1 Oil, leave it for a while, and see if that loosens it up.
As to fitting the lights, there are many, many different types. If you can find out the name of the lamps that you have, it might be worth doing a search on YouTube for an instruction video, because there will almost certainly be one. HTH