what is a good sword and shield weapon?

Well i would like to know what are some good SAS are and also some  great swords I am just getting back in this game so i would like the help thanks in advance (oh also can you recommend am 2 rank mission thank you again)

Choose the one that has the highest element to the corresponding weakness.

SnS revolve around Element or Status, so the more of either, the better. Don't neglect raw though, because you will not always have the reach to get to a monster's elemental weakspot.
Basically, here's a list of the best elemental/status Sns:
Fire: Bone Kris -> Bone Kris+ -> Bone Tomahawk -> Bone Tomahawk+ -> Qurupeco Chopper -> Djinn ----> Golden Radius. Megiddo Edge is also good, but unavailable until the final G-Rank quests. Fire is pretty rare on SnS.

Water: Sea Striker ----> Arken Duelcalion. Odyssey Blade has superior element but slightly lower raw, but requires Awakening, which is, like the weapon itself, unavailable until G-Rank. Bone Kris -> Bone Kris+ -> Ludroth's Nail -> Royal Claw ----> Harmetristesse is a good alternative if you don't like farming (Goldbeard) Ceadeus.

Thunder: This one's a little more difficult. There are 5 end-game Thunder SnS. The only Low-Rank Thunder SnS is Bone Kris -> Bone Kris+ -> Bone Tomahawk -> Bone Tomahawk+ -> Lagia Sword ----> Neodignis Whitebolt. Neodignis Whitebolt can be upgraded to Nether Lifesword or Nether Maestral; the former has slightly less raw and element than the latter, but is slightly easier to get. Hunter's Knife -> Soldier's Dagger -> Commander's Dagger -> Hypnos Knife -> Azi Dahaka -> Azi Dahaka+ -> Usurper's Firebolt (yes, it's Thunder element) -> Despot's Crookbolt -> Oppressor's Bounty has a lot of element, but is a little lacking in Raw. Sanctioned Sword has even more element, but has also even less raw. Finally, there is Qurupeco's Flight -> Qurupeco's Blight, which is unavailable until early G-Rank. It's better than the High Rank versions of the aforementioned weapons, but inferior to their fully upgraded versions. Personally, I prefer the Nether Lifesword (haven't had the time to farm for Nether Maetral yet), because it's the most balanced of them all.

Ice: apparently, Capcom hates the cold, so MH3U has few good Ice weapons. The only 2 good late-game Ice weapons are Hunter's Knife -> Hunter's Knife+ -> Hunter's Dagger -> Assassin's Dagger -> Icicle Spike ---> Nardebosche -> Nardebosche+ ----> Gran Bhavani. And Tusk Gear ----> Chalcomatia, which requires Awakening though. Both lack very high element, but they have good raw. Only the former is available before G-Rank. And oh, ya, there's the Secta Nulo -> Secta Una ---> Secta Du (W), but you shouldn't get this one unless you are very, very, very, and I'm talking VERY desperate for 3 Slots on your weapon.

Dragon: there are 3 good late-game weapons with Dragon Element. Worn Sword ---> Divine Insodus has a truly ridiculous amount of Dragon (700), but like no raw at all.  Jhen Kodachi ---> Earthsbane Gladiolus has very good raw, but mediocre element. Finally, there is Alatreon Sword ---> Altheos Zodiarch, which has good raw and good element. The Altheos Zodiarch is the best of the 3, but by far the most difficult to get. Oh, and if you happen to stumble upon a Rusted Sword before G-Rank, feel free to upgrade it. It's decent enough, though like it's Ancient counterpart, has low raw and high element.

Ugh, too much time spend here. Maybe I'll post the best status weapons here later, but for now, this will have to do.

Ahhh thank you so much this did help looks like am going for the Nether Lifesword thank you again!

As has been stated element / status is more important with SnS than any other weapon, so you'll want at least a few so you can use something appropriate.

If you were going to go with just one I'd suggest the Hunter's Knife>Shadow Saber>Hellnox Epee, there aren't many monsters that poison is bad for, and a few where it works really well.

I'd back it up with Hunter's Knife>Icicle Spike>Gran Bhavani, it's got good sharpness and nice affinity boost; and Bone Kris>Quru Chopper>Corona.  With those 3 you'll have good options for almost every monster.

KIRITO doesn't use a shield noob.

the bug sns....do eet!

divine insodus is quite good. Only SnS i use and I use it with element attack +1 honed blade

If I could use 1 handed swords I would.