If you read the information in the link I provided, you will see the definition of a "financial account", and no, assets such as a car or house are not included.
In general, going forward, you will be better off filing MFS. That means only your income is reported, not that of your spouse. After meeting the requirements, you can either exclude your earned income or use FTC to offset US tax due (if any) by taking a credit for UK tax paid (or accrued). Your worldwide income is always reported on the US return. since you did not marry until January 2019, for 2018, your status is still single, not MFS.
Buying a house is not a taxable event. There are other considerations that may result in tax implications in years to come, which you should consider when you buy,. but no, an accountant is not required to file a tax return when you own a house. Many of us do.
There are lots of IRS publications that you should read and try to understand, one being Publication 54.
https://www.irs.gov/pub/irs-pdf/p54.pdf The more research you do, the better prepared you will be when you file for 2019. That may seem a long time away, but there are things you can do to prepare for the dreaded filing that you can't avoid.