If you are an individual owner and your LLC has one owner, you are typically considered a Single Member Limited Liability Company (SMLLC).  If this is the case, for federal IRS filing purposes the activities of the SMLLC will generally be reflected on one of the following forms depending on the business activity:

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

In this case, you can report all your business income and expenses on a Schedule C, Schedule E or Schedule F as part of your personal income tax returns. The Turbo Tax software will pass the profit through to your 1040  (your SMLLC is considered a disregarded entity for federal income tax purposes).  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. As a SMLCC, you can use either your social or an employer tax id #. A single-member LLC that is a disregarded entity that does not have employees and does not have an excise tax liability does not need an EIN.

https://turbotax.intuit.com/tax-tips/small-business-taxes/llc-tax-filing-rules/L39E29kPR 

In terms of state forms for a SMLLC, most states do filing requirements and minimum taxes due depending on the state in which you operate your business. To find the annual reporting and tax requirements

https://www.nolo.com/legal-encyclopedia/50-state-guide-annual-report-tax-filing-requirements-llcs 

However, if you are a multi-member LLC, then the above would not apply and you would have a few entity choices: 

1. The default is to be treated as a partnership
2. You can elect to be an association and then taxed as a C corporation
3. If you are an association you can also elect to be treated as an S corporation
4. If it is a husband and wife and are in a community property state, they may qualify as a qualified joint venture. You would the file the appropriate corporate tax returns depending on the type of entity you have selected.