From the Accounting point of view you need to consider if your first home should be a single family house or a 2 family house (or multifamily). Depending on your situation, you may opt to choose a 2 family home perhaps to help you out to pay the mortgage since you will have rental income from the apartment that you would rent out. But keep in mind that when the time to do your Taxes come you can only deduct half of the interests paid and half of the property taxes paid (Itemized deduction on Schedule A) since you are occupying half of the house as your primary residence, the other half is considered as business/investment and you are collecting rent and you will need to report the rent collected and of course you can deduct the other half of the interest and property taxes, also you will be able to deduct repairs and maintenance to the rental apartment only not the apartment you occupy, half of insurance cost and depreciation (rental income and expenses on rental apartment are reported on Schedule E)
Another important issue when buying your first home is that on a one family house, if you live there for 2 years and you want to sell your property, you don’t have to pay taxes on the first $250,000 capital gain (purchase price minus selling price and closing cost); in other words If you have a gain from the sale of your main home, you may be able to exclude up to $250,000 of the gain from your income ($500,000 on a joint return in most cases); this is no case on a 2 family house since you only occupy 50% of the house and the other 50% was used as a rental property.