Hi there and welcome to the hobby ! Don't worry, i made most of the mistakes you did, and a few more, so you haven't done too badly. As long as you learn from them, you'll do fine.
Lords and Heroes - Your lord... He has no survivability. which is bad, because one canon shot and your enitre army is taking damage, and then you're relying on someone in heavy armour to survive for the rest of the game. Rule one about vampire generals is that you need to have a ward save on them, they're just too valuable not to have one. they need to live, and in this many points you just can't fit a ghoul king on a terrorgheist and have it be viable. It neds a ward save, but don't worry, you can fit another terrorgheist in your rare section. You could feild a normal ghoul king, but i wouldn't, as they can't take armour due to the armoured mage specail rule.
That leaves you with a Master necromancer or a Vampire lord as your general. A master necromancer is your cheap high level magic user without all the bells and whistles,l but you probably don't want him as you have mannfred the accolyte doing all your magic for you. That leaves you with a vampire lord as a general. Now, you probably want a fighty lord, so don't buy too many magic levels, but its not that great to put too muich emphasis on his fighting. (golden rule of warhammer - super-fighty characters are never worth it - units will do more damage) you'll want some magic armour and also a ward save to protect him. HE should work out much cheaper, and won't get shot down quicker than you can say "fire magnet".
Mannfred looks fine, personally i'd use a level 3 or 4 lord and a level 2 vampire for my magic needs, but this mix of magic levels could work just as well.
Core-Looks fine, you have your 2 main units, one for each vampire. a horde of ghould will kill pretty much anything of the same size (if it's core) i would suggest you include a squad of zombies as well,because raising sounds great in thoery, but now you can't focus raise, they basically give away free victory points. so chuck some of those inl, and maybe drop down to 2 sqauds of 30 ghouls, beacuse by your turn 2 charge, you shouldn't have too many casulties.
Specail - i love mt hexwraiths, but are you aware they come in boxes of 5? if you have 6, take 6, otherwise, drop the squad to 5. if your planning on using the soul reaping move, you don't really need the champion, so you can drop him.
Rare - Terrorghiest, fine great choices in your rare. You didn't fall into the classic pittraps of giving it all the upgrades under the sun which is god. i wouldn't use 3 cairn wraiths, They'll die to combat res. either up that to a squad of 5, or take something else in your rare, such as a black coach or vagulf (both solid choices).
Hope you have fun in the hobby!