House hack (roomate) tax strategy

[Tim Hertz]

Here's my question......I just got a roommate. He pays $425 plus half the utilities. He rents 2 bedrooms from me and a garage space in my single family home (4 bed/ 2bath). My question is on the best tax strategy for what I am wanting to do both long and short term. Which expenses can I write off now without shooting myself in the foot when I go to sell the place or rent it out? 

I either want to sell the house with no capital gains after two years OR rent out the whole house after a couple years. 

I bought the house for 38k and have about 7k in rehab and hope to sell it around 75k.

Thanks for your reply in advance!