Welcome to the family. I started playing magic a couple months ago and was more or less in the same position, building a deck out of the toolkit/cards I had gotten in a draft. Something most experienced players do when building decks is use multiple copies of cards rather than tons of different creatures/other spells. It makes your deck more consistent which will give you a better feel for the draws your deck is going to give you

ok so now to try and be actually helpful. If you want to do a black white life gain type deck that is relatively inexpensive and uses a few of the cards you already have, a friend of mine runs a Festering Newt , Bogbrew Witch , Bubbling Cauldron , Angelic Accord B/W life gain deck that makes angel tokens. B/W gives access to good removal like Doom Blade and enchantments like Pacifism . I am sure with the interaction of the cauldron, newt and witch you could find some fun life gain stuff to do with your Oreskos Sun Guide , Servant of Tymaret and Sunbond

I'm not current familiar with the standard meta game so I am going to offer you more general knowledge.

First, your average converted mana cost (CMC) is a little high. Try to get to to 3, or less. This will allow you to do more earlier on in the game. The mana cost of your spells should resemble a pyramid - you should have lots of things that cost 1 and 2 mana, some 3 mana stuff, some 4 mana stuff, and then very, very few 5+ mana cost spells.

Second, try not to spread yourself out so much. As a new player it is easy to make the mistake of thinking Magic is mostly about getting lucky with draws. As you mature as a player, you will see that one of the most important aspects of Magic is reducing your reliance on random chance. You want your deck to be as consistent as possible. To that end, try running 3 or 4 of the same copy of a a few different cards, rather than 1 or 2 of many different cards.

Third, try to keep in mind that standard is turn 5 format. That means your deck should be able to do 20 damage to your opponent by turn 5. If it can't, you should have ways to slow the game down, such as with life gain and with removal. Doom Blade is an example of removal.

tl;dr

Run 4 Child of Night , 4 Soulmender , and remove all your spells that cost more than 5 mana, and add more removal like Doom Blade

Okay first things first, focus your deck to what you want it to be I.e lifegain. You should take out all things that does not help with the idea (with the exception of removal and lands) so i would suggest removing Accursed Spirit and Minotaur Abomination for now and replace them with two more Angelic Accord s. Then you need a way to gain at least 4 life each turn. That is where the bogbrew witch and her cauldron full of newts shine, with the following card : Trading Post . Think about the posibilities with this card and the synenergy it has with that combo, sac your newt gain 4 on your turn get angel token, in the opponent turn make a goat token and sac for 4 and get another angel token, look carefully at each card's ruling and what is there but look especially for what is not there (like what you can do at instant speed etc. ). If you need any help feel free to contact me!

What kind of deck did your friend give you?

lookoutimscary, my friend gave me a red/blue deck. I played with it a couple of times. The deck wasn't that strong from what I noticed, but it was complete enough to give me a decent understanding of the game.

Ah, ok cool. Sorry for asking, I recently got a friend into MTG by giving him a deck and he bought a Toolkit and built a W/B lifegain deck also and I thought that might be you but apparently not.