I have a day job with W2 and i started a LLC with a friend,

Since the LLC has 2 members, you will have a couple of options.  

You will either file as a partnership on Form 1065.  You will report the activities for the LLC on the partnership return.  Each LLC member will then receive a Schedule K-1 which is used to report any pass-through income or loss on your personal returns.  

The other option is for the LLC to be taxed as either a C corporation or an S corporation.  Please see this link for more details to help you decide what the best option would be for you. Be aware, there are other steps that need to be taken if the LLC wants to be treated as an S corporation.  S corporations also issue a Schedule K-1 to each of you to report on your personal tax returns, but a C corporation will report all income and pay all taxes on the business return.

Please see Limited Liability Company (LLC) from the IRS for links to the specific forms that would need to be filed depending upon which route you choose to take.  You will also need to check your state Department of Revenue as sometimes there are different reporting requirements or registration numbers that may need to be obtained depending upon the state.

Whichever option you choose, you will enter all of your business income and expenses on your business tax return.  

A few additional comments:

• Based on your initial question(s), I believe you should seek some tax advice as to the best entity structure for your needs and goals.  Don't be penny wise and pound foolish here as it can cost you significantly more down the road.
• Based on your limited facts, the default entity structure is the LLC will be taxed as a partnership.
• You can make an election to change that structure, but I recommend you get help so you understand the differences.
• You don't indicate whether or not the business has actually "started business".  This is key in determining when you will have a return filing requirement.  
• When you can deduct your current expenses, depends on whether the business has actually started, or whether the expenses need to be capitalized and then deducted as either start-up expenses or organizational expenses.  A tax professional can help in this area as well.