If you want to run a business - you generally may simply act as a physical person and do not need to have an LLC.
Whether having the LLC is a suitable solution depends on your circumstances.
For some riskier businesses when you want to protect your personal assets - that is suitable. If you want to run the business via separated entity - that also works.
However - if you want to protect the money and other assets from tax levies by putting these into the LLC - that will not work.
If you have a tax lien - the best solution would be to negotiate a payment plan and stay current with that plan.
Please be aware regarding the difference between the lien and levy.
A tax lien is the government's legal claim against your property when you neglect or fail to pay a tax debt. The lien protects the government's interest in all your property, including real estate, personal property and financial assets.
.A lien is not a levy. A lien secures the government's interest in your property when you don't pay your tax debt. A levy actually takes the property and/or income to pay the tax debt. If you don't pay or make arrangements to settle your tax debt, the taxing authorities levy, seize and sell any type of real or personal property that you own or have an interest in.
Let me know if you need any clarification this matter.