@Geri May I agree with @Rachel Mazzanti That you want to set it up right to begin with to be better down the road.
When it comes to Specific "Codes" I am not sure what you mean. If you mean like a number system, from what I have experienced: Assets start with 1, Liabilities with 2, Equity with 3, Income with 4, Cost of Goods/Service/Expenses related directly to Income is 5, Expenses are 6, Other Income is 7, and Other Expenses are 8. You can choose how many numbers you want after that but plan on what you see the end goal would be. Got lots of Assets and Notes due? start at 10000. I have seen some go 10-001 but the starting digit follows that "code" in Accounting from where I have been and learned.
Travel to me is a parent account because if you spend money on traveling to see a property, that expense is allowed to be included in the basis of the asset purchased. But over time the IRC has changed on how meals are tax deductible so Travel meals were 100% allowed while non-travel meals were 50%. This has changed and will change again in the future but it is broken out to also help YOU read YOUR Financials. Rehab, above a certain threshold should be an Asset because you are affecting the life of the asset so it would be in the "1s".
Hope that helps! Good luck!!