Can I file my personal and business taxes at once?

That depends. If you are the only "member" (owner) of the LLC then yes (unless the LLC has elected to be taxed as a corportation by filing Form 8832).

The IRS website says this https://www.irs.gov/businesses/small-businesses-self-employed/single-member-limited-liability-compan...

Owner of Single-Member LLC

If a single-member LLC does not elect to be treated as a corporation, the LLC is a "disregarded entity," and the LLC's activities should be reflected on its owner's federal tax return. If the owner is an individual, the activities of the LLC will generally be reflected on:

• Form 1040 Schedule C, Profit or Loss from Business (Sole Proprietorship) (PDF)
• Form 1040 Schedule E, Supplemental Income or Loss (PDF)
• Form 1040 Schedule F, Profit or Loss from Farming (PDF)

An individual owner of a single-member LLC that operates a trade or business is subject to the tax on net earnings from self employment in the same manner as a sole proprietorship.

If the single-member LLC is owned by a corporation or partnership, the LLC should be reflected on its owner's federal tax return as a division of the corporation or partnership.

See this TurboTax FAQ on which version of TT you need. <a rel="nofollow" target="_blank" href="https://ttlc.intuit.com/questions/1901017-which-turbotax-do-i-need-to-file-as-an-llc">https://ttlc.intuit.com/questions/1901017-which-turbotax-do-i-need-to-file-as-an-llc</a>