This may sound stupid, but I keep trying to make a good mix of oil & vinegar. I always get it to where the vinegar is too strong or the oil is too much. Any ideas on how to even it out so its not so strong or oily? I buy the store bought oil & vinegar dressings, but to me the vinegar is still a tad too strong. Can anyone help out? I would appreciate it.
The only stupid question is the one you don’t ask 
To make a vinagrette, the classic combination is 1 part vinegar to 3 parts oil (i.e. 1/4 cup vinegar and 3/4 cup oil). There are about as many different recipes for vinagrettes as there are people in this world. I would start out with this ratio, and see what you think. Also, if you like O/V dressings, you should experiment with different types of vinegars. For example, apple cider and balsamic vinegars are sweeter, so if you use 1/8 cup balsamic and 1/8 cup apple cider to 3/4 cups oil, you won’t have as much of a “vinegary” bite as with plain old distilled white vinegar. White sugar is also used to remove some of the acidity from vinagrettes. Finally, dijon mustard and ketchup are two common ingredients added to vinagrettes for flavoring. Addition of either one requires a good whisking so that the dressing emulsifies. Good luck with your dressings, and let me know if this helps!