LLC's are handled on a per state basis not nationally.
Step 1 - Pick the state you want to form your LLC in. Some do not allow foreign owned officers.
Step 2 - You will need an official business address.
Step 3 - File your LCC
Step 4 - Request an EIN with the IRS (free)
Step 5 - Open a bank account using your LCC name and EIN
In states such as Wyoming, Nevada and Delaware it is quite common to find law firms and individuals that offer full service. They can be your registered agent since you are not in the states. Most offer mailing addresses. They can file your documents with the state and even request an EIN on your behalf.
I have never seen anyone get an LLC or INC without an address.
Dont let that deter you. In the USA an address just has to be a mailing address.
Most will not allow a PO box, but will allow a box leased out at a UPSStore or other virtual office setting.