Welcome to Spark People !
If you want to see more definition in your body (seeing more muscle), then you need to do some type of strength training. I don't know what books are available in Spain, but you should look for weight training and strength training books for women.
a great website to help you learn strength training is this one. It has some beginner workouts you can try. Do what you can to start. www.stumptuous.com/
And look at the SP fitness section. Coach Nicole also has some beginner strength training workouts posted too. All you need are some hand weights or resistance bands.
Also, ask your friends what DVD workouts are popular in Spain right now. I don't know what US DVDs you can get in Spain. Some popular workout DVDs here include the 30 Day Shred, Zumba, P90X, etc...
Do you have a gym membership ? If not, you might consider joining a gym to take classes and use their equipment.