Work for that trucking company for a year while you learn the ropes.
Eliminate all unnecessary bills
Start saving money
Don't buy unneeded stuff
Think of a company name
(If you include trucking in the name getting a business loan might be harder. Consider using Enterprises instead. Up to you though)
At 3 months or so if you're loving trucking so far
get a virtual address and phone number. Check to see if your trucking company name is available and start your LLC as a sole proprietor. Get your EIN number from IRS.
Open Business bank account. Get your Dunns number. Write a check from your personal account to your business account each month to make a $200 deposit. Start building your business credit. Order office supplies on time from Grainger.
After 1 year of trucking if you still want to start this trucking company, get your DOT number. You will have 3 months to get your insurance. You'll need probably $10,000 to get up and running.
You shouldn't have a problem buying a truck. Get it financed at the credit union (preferably) or bank you have the business account at.
With the questions you're asking, this is how you should start. Don't worry about trying to get a grant to start a trucking company right now because you don't sound like you're ready for that.