Generally shielders are more team orientated, you'll be the guy distracting the enemy / saving friends / taking arrows to save others / leading the way in tricky defensive spots / surviving slightly longer in some situations. The average shielder will not get as many kills as the average 2H player.
I like the build 21/18 personally. 21/15 is a solid beginner build, but it's a team based build -- You will be kyted like hell by people and you will find yourself missing hits and being spammed.
People advise you to avoid 2Hers because they can out damage you, outspam you, outreach you and outrun you. Well, you can't avoid someone who comprises 70% of the melee force on your enemies side and can run faster than you due to not lugging a shield around. Sure, run away when you're outnumbered and stick with your team, but the reality is you need a bit more speed to deal with these people sooner or later.
You're inherently outclassed as a 1H. Your weapon, being lighter, will be stunned when blocking by heavier weapons. With its lower reach, you'll have to block at least 2 times when approaching someone with a 2H / pole arm weapon before you can hit them back. Your fastest and most used attack mode (left swing) is also incredibly predictable.
You need 18 AGI, 6 ath and 6 WM (if possible) to keep up with the big boys if you want to be able to stand on your own two feet on the battlefield (Do not get below 7 PS or you'll weep when using cutting weapons). Wearing lighter armour will make you a bit faster, but it's a double edged sword. You'll die faster and while "MY SHIELD IS MY ARMOUR HERP DERP" it's simply impossible to not get some hits when dancing around with a group on you. but 21/18 allows you to dodge and weave in group situations like a boss, it allows you to keep up with the big boys and deal serious damage when you get there and it allows you to bob in and out of combat with people who are used to being the fastest.
Get good at manual blocking and shove your shield on your back in 1v1 situations, especially vrs an axe user. Only use your shield when ranged are attacking you or you're taking on multiple people who you believe would get free hits on you if you were to manual block in that situation. Your shield slows you down, movement wise and swing wise.
Weapon wise, I prefer to get as close to or above 100 range as possible and the same with speed. Range will help with swing speed too, you'll find yourself moving forward a little less often which means you're not giving up your "swing turn" to the 2h'd AGI spammer backpeddling you meaning he cannot spam you with impunity. As others have said, weapons that don't stab are good starters such as the Elite scimitar or scimitar because you won't accidentally pop off a failed stab attack which will whiff and make you rage like a man possessed -- They're also fast, long and hit hard (they have the added bonus of being curved too which is deceptive and people misjudge your range, you seem to whiff less closer to people as well). Personally I like the Nordic war sword / Nordic champion sword.
It might be worth getting 2 throwing skill and 50~ wpf in throwing. You'll be amazed at how helpful a stack of war darts or a couple of francisca throwing axes is as a 1H player. You won't sacrifice too many skill points (maybe loose out on ironflesh and maybe drop to 4 shield skill). But what you'll gain is the ability to get kills on people from a distance (Granted, not often with that low throwing). But most importantly, you'll have the threat of range, this means you can let a AGI spamming back peddler walk back like the monkey that he is and pull out your throwing weapon. This puts him in a dilemma as he has to come back to you or leave you alone. Horses will avoid you like the plague too, and you'll have a handy weapon to kill or stun archers who are running away from you. Beware of the extra weight they cost though.
