I have been trying to balance my trial balance but I'm giving up can't find the error
Cash;600
Truck;1100
Capital; 17000
Supplies;300
Cash 300
Prepaid insureance;700
Cash ; 700
Cash;800
Service revenues; 800
Salary expese;700
Cash; 700
Cash;12000
Service Revennue;12000
Cash;600
Unearned service revenue;600
Cash;1500
Account Receivable;1500
Fuel exp;200
Acc payable;200
Acc receivable;900
Service revenue 900
Rent expense;600
Cash;600
Acc payable200
Cash 200
Withdraw;2100
Cash ;2100

You have accounts listed more than once.

It appears they are journal entries. The first one does not balance

It should be:
Debit Cash for 600
Debit Truck for 1,100
Credit Capital for 1,700
(for owner investing cash and a truck into the business)

Once you journalize your entries you need to post them to your acocunts, then get your account balances, then you do your trial balance.