White Green Black +1/+1 (Standard)

This is my first attempt at a deck in MTG Online. My goal is to keep the costs low, and I've sunk about $20 into it so far. I don't plan to spend much more.

The strategy is to use +1/+1 counters to give abilities to my creatures like lifelink, flying, deathtouch, first strike, trample, and such. There is limited control available through the Citadel Siege, Utter End, Dromoka's Command, and Abzan Charms.

My goal is to win through a combination of limited control/removal and overpowering creatures in the mid-game. As I am playing with this deck, I am seeing a weakness to heavy control decks and decks that use lots of small creatures.

The sideboard is a list of cards I used to use but have replaced with something else I thought more powerful or more flexible. I do not intend on using them in this deck, but put them in here if you wanted to see my thought process. I'm open to ideas for real sideboard cards.

Any tips or thoughts are greatly appreciated.
Thank you for your time!