Buses run from outside the station, that being Jesenice Zelezniska postaja, to Bled, and the same buses carry on all the way to Ljubljana. It costs 590 SIT, to Bled, and takes about 24 minutes. The bus to Ljubljana runs every hour for most of the day, from 5:30 am onwards, costs 1520 SIT, and takes about one and a half hours. You can get more details on times and fares in the link below.
Well, if you are in Jesenice, chances are you are either getting on or getting off a train, and bound for some other part of the country. Trains on the Ljubljana - Munich line stop off here, just before they cross the border into Austria, so if you are trying to get out of the country, this is the place to be. You can also get off the train here if you are heading for Bled from Austria, and get the bus the rest of the way. That will probably save you money, as Austrian trains are a quite expensive. It will also save you some effort, as the buses from Jesenice to central Bled are more frequent than those from Lesce-Bled station and central Bled, which are a good four kilometers apart.
Jesenice station doesn't have platform numbers, at least none that I could see. As far as I could work out they were numbered 1, 2, 3, etc. from the line furthest to your right as you face Austria to the north. That's probably of little use to you, so just try sign language with one of the helpful station officers. You'll probably have plenty of time to work it out before the next train comes anyway.