Is this the first time you are registering this vehicle?
It is the first time I am registering it, but, no I have not registered it yet nor paid any of the fees.
Is there a MCTD 1 fee if I register my vehicle in Suffolk County?
Yes, Suffolk County is one of the twelve counties that does impose the MCTD 1 fee.
Are the charts that I have found online to estimate fees and taxes applicable to commercial vehicles?
The charts that you see online that give those estimates are applicable to commercial vehicles, but they do not include the sales tax.
What other information can I find on those online charts?
You can use these charts to estimate your registration fees, use taxes, and supplemental fees for passenger or commercial vehicles.
Are those online charts also applicable to trailer registration fees?
You can use them for passenger and commercial vehicles, which, unfortunately a trailer is not.
If I paid the sales tax when I bought the vehicle, will I still be charged that tax when I register it at the DMV?