First question - are you in a club? If so...then ask your club.
If you're just starting out, then synthetics might be your best bet. You don't know yet just how serious or long term your training will be. A good synthetic will cost you around $120 USD. A basic steel trainer is at minimum $200 USD, and the better ones are at minimum $260 USD. So, for the cost of one steel, you can get two synthetics.
It's really important to stress that synthetics are not, in fact, any safer than steel. They can still break fingers, damage someone's throat in a thrust, or cause a concussion. Slow play is still recommended until you get better protection.