Oooh! I got my Ace of Spades on a Spider, years ago - it was before half of the weapons we have now were in the game.
Spiders are underwhelming, though. It's a matter of hardpoint count and architecture - but that's ok! You can still have a ton of fun with the Spider.
General points first; obviously you're not going to be able to boat anything on most Spiders (the MG variants being the exception,) so you need the most bang for your buck. That often means not taking your max engine rating, and picking weapons that may be larger than typically found in Lights.. With jump jets, depends on if you need the tonnage for the build. The Spider jumps well, and since you're actually outgunned in close combat by almost any other Light, being mobile can help you break contact and escape - but you've still got to buy guns first.
With the Spider 5D, my old Build was an ERLL, and two Medium Lasers, but that's harder to use. For current play, I would use Light PPC builds - like
This One, from GrimMechs. The 5V's choices are dual MPL, or a single LXPL or SNPPC - all of them will underwhelm you, and the 5V can't go unnoticed as well as the 5D; not just because it lacks ECM, but because its main benefit is that massive cooldown quirk - and that means you have to seek more facetime with the enemy.
Now, in Tier 5, it's a LOT more about how you're driving a 'mech than how good the 'mech is. The spider is still pretty agile, and has some modest durability, so work the sides of the fights that are happening between bigger 'mechs, and reposition if people start waiting for you to pop back out of cover again. Use jump jets to reach locations other pilots can't reach,
and to spread damage (along with torso twisting) when you're getting shot at. Use your mobility to look around a little, so you can see how the battle is flowing and don't get caught off-guard... that's about it.
Everything else is self-reflection and intelligent practice. =]