Much of what you are asking is about proper accounting practices, so there isn't a "yes" or "no" answer. Going forward, it would be a very good idea if you contact a local CPA for assistance in properly reporting your business's transactions, both for 2020 and 2021.
Until then, the following should help:
You stated that $75K of the purchase price was for inventory, but you can't sell fuel without a physical location and equipment. In almost all cases, you also need a franchise and/or a supplier agreement (Assets). The "physical location" might be a leasehold (also an Asset) or real property purchased outright (you didn't mention a mortgage, so I would first assume a leasehold).
After allocating the $275K to the FMV of tangible and intangible assets, any remaining amount is allocated to "goodwill", also an asset.
On a business balance sheet, Assets = Liabilities + Owners Equity. We covered the basic assets above.
If you funded the entire purchase price of $275K (no borrowed funds), then Liabilities = "0".
For the Owners Equity part of the equation, a nominal amount (e.g. $100 or $1000) is typically allocated to "Capital Stock", and whatever remains of the $275K is allocated to "Paid in Capital". This results in a "balanced" Balance Sheet at the beginning of your operation.
If you subsequently have a loss from operations, it is recorded in the "Retained Earnings" account as a negative balance - this is an Owners Equity account,. When you lose money, your investment ("Equity") in the business goes down.
In answer to your 2nd question (increase the loan base?), to keep the balance sheet "in balance" you'd have to borrow from a willing lender (a Liability account), or invest more (Additional Paid in Capital). The "willing lender" is most often you, the owner/shareholder (i.e booked as a "Shareholder Loan" - a Liability account).
Your questions #3 and #4 can't be answered accurately until 2021 results are properly recorded and a sales price established. This is where a local CPA could be invaluable. Keep in mind that TurboTax Business is a tax preparation program, not an accounting program. You can use Quickbooks for your accounting needs, but even that program requires some knowledge of proper accounting procedures.
