To save money, you can make the oval a dirt or clay oval if you have the right soil (dense clay). I presume that labor in your country is relatively inexpensive; I don't know what your access to financing is, but the asphalt is your greatest expense. It consists mostly of oil the tar component) so wait for oil prices to drop as low as possible.
An American drag strip is a very simple operation. You will have a scoring tower, a public address system, some aluminum bleacher seating, poured concrete or cinder block safety walls lining the track (very important), the starting lights, a large scoreboard to display times, an optical light-based timing system to determine elapsed times, race winner, 60 foot times, and normally 330 foot and eighth mile times.
Also consider, if you don't have enough land area, you can build an 1/8th mile drag strip, which is also very fun and growing in popularity. Many larger tracks started with an 1/8th mile and expanded to a quarter mile later on, either with funding or once the track as made some money.
Other additions: have a large, paved parking lot which can be used as a paddock by the racers, and also for skidpad testing, autocross and gymkhana. If you have enough land, you can set up areas for motocross, rallycross and other off-road activities which just require some clearing of vegetation and earth moving.
If you are serious, there are a number of facilities like that in Northern Europe, or if you like to travel, a nearly endless number North America. Look through a website called Trackpedia and you will see a huge variety. Most have websites with photos, so you can easily see what kinds of facilities they have, and what sorts of schedules they run.
Good luck!
