Your compound's empirical formula is
To determine exactly how many atoms your compound contains, you can use its molar mass, which tells you what the mass of 1 mole of a substance is.
In your case, the molar mass is equal to 88 g/mol. This means that, if you add the molar masses of each atom that makes up your compound, you'll end up with 88 g/mol.
You know that your compound contains at least 2 carbons, 4 hydrogens, and 1 oxygen. Use their molar masses to get
Thus, your compound's molecular formula, which contains all the atoms present in the molecule, will be