You'll probably get as many answers to this as there are members here
There are a number of things to consider and I suppose the first is have you done any painting of any kind before? If you haven't then Vallejo and Andrea, the two most common hobby acrylics, might not be the best choice as they dry very quickly and many people find them tricky to master. But they are easy to use for simple painting and their fast drying time can be an advantage as well.
Oils might be more forgiving because they give plenty of time for blending but many people find they are better suited to larger scales. They also come in intense colours mostly so you need to learn to mix the dull colours that are common in our subjects. Hobby paints on the other hand are available in a range of ready-made military shades like olive drab, khaki and field grey, as well as a number of fleshtones.
Enamels are another possibility by the way, Humbrol being the most common, and these can be used together with oils - the most famous figure modeller uses this combination. In some respects this is the most versatile option as you have a relatively fast-drying paint, the enamels, and the slow-drying oils which can be mixed together or used sequentially for different effects.
Lastly you should consider cost. Oil paint can last almost indefinitely in the tube, and the quantities we use are tiny, but they have a high initial cost -
very high for some colours, $40/50 and more for one small tube. You can paint a figure with only four paints if you know how to and you don't mind all the mixing but realistically a palette of about 12-15 tubes isn't unusual and many people have a lot more than this.
In the long term oils work out to be very inexpensive but if you just want to try your hand I think it would be best to stick to hobby colours where the initial outlay is low. And since many people find mixing believable skin colours difficult this is another advantage to a range like Vallejo which has a number to pick from.
Don't forget that you'll need brushes too and although you can get by with only one or two most people use a few more on a regular basis (again it depends on the scale of the models to some extent).
Einion