If my dad passed away and I was the only child and he wasn’t married would I get all of his belongings?

If your dad passed without a will, unmarried and with no other siblings in Michigan you are presumptively his only heir. If your uncle took anything from his estate yes you can get it back. You will need to file a probate action to become the estate's personal representative and then be able to sue your uncle to get it back.

If your father did not have a will he is considered to have died intestate. The laws of Michigan detail how the estate of an individual who dies without a will should be divided. The spouse is the first person to receive the inheritance. If there is not surviving spouse then the estate is divided between the surviving children. If you are the only living child, then you should receive the entire estate. Your father's brother is a collateral heir who would inherit only if there were no surviving children. It sounds as though no one has filed a petition with the county probate court to open your father's estate and be named personal representative. You should do this immediately. The personal representative (PR) of the estate can require all assets taken from the estate without court approval to be returned to the PR for distribution under the statutory scheme. You may want to retain an attorney if the estate has value.

See an attorney, you MIGHT have a claim but time is running. Get to an attorney with the details. Although you might be the presumed heir at law, that can be negated by the titling of assets, wills and trusts.

From what you have said you should be the only person inheriting. You should consult with an attorney about what to do.