Oil vs. Acrylic Paint
What are the differences?
Many beginning artists feel that painting with acrylic paint is easier to work with than oil because it dries very quickly, and it is easier in terms of clean up, as you only need soap and water. However, I think you should explore each for yourself as they both have their pros and cons. For example, oil paint has richer color as it usually has more pigment to lake, making the color more vivid with greater depth. Oil paint usually remains the same color through the drying process.
Acrylic paint has a more surface(y) color, sometimes described as having a plastic look. The acrylic paint colors will dry a little darker then they look. The real difference in working with each is the drying times. Acrylic paint will dry within an hour, if not within minutes if no drying retarder (e.g., Golden's Acrylic Paint Retarder) is added. Oil paints will stay wet for days or weeks, depending upon the type of pigment, humidity, and temperature factors. You can add a dryer to the paint (e.g., Winsor & Newton's Liquin) to speed up the drying process.
There are real advantages and disadvantages to both. If you are trying to blend wet into wet paint as is done in many portraits, oil will provide you with a better environment for such rendering. If you are painting dry brush technique or want to work in a very fast action, painting over dry paint, then acrylics would be a better choice.
I would encourage you to experiment with both. As you develop your own style of self-expression, you can make a decision as to which, if not both, serves you best.
You can start paintings in acrylics and when they are dry you can paint oils over them. However, you cannot paint acrylic paints over oil paint due to the basic physics principle of oil and water not mixing. The acrylics will not adhere to the oil paint and will bead up and peel off.
With experience in using oils and acrylics, you can get expert enough to paint any subject with either and it will be almost impossible for the viewer to distinguish oil from the acrylic paint.
Below are a few master paintings painted with oils and acrylics.