Eastern Europe tour

You can go by train with at least one change which takes almost 6 hours. You'll be waiting in Villach almost 2 hours so maybe you can look around. Train leaves Lake Bled 8:13, arrives in Villach 9:08, leaves Villach 10:50, arrives in Venezzia - Santa Lucia at 14:05. Some other connections are faster but you have to change trains two or three times. Check Deutsche Bahn website for other options.

There is a good and easy train connection with only one change: Bled Jezero (a short taxi drive from your probable accommodation) to Nova Gorica (the Slovenian railway station at the border), taxi to Gorizia Centrale (the Italian railway station in the same city), where you take a direct train to Venice. Journey time is around 5h30, including a 40 min connection time between Nova Gorica and Gorizia Centrale. (There is a regular train service between Gorizia and Venice, so no problem if you should somehow miss the first connection to Venice.) The leg between Bled Jezero and Nova Gorica is stunning.
You can find the schedule on this European railway planner. It's all by regional trains, so no need for reservation or advance buying. Bled Jezero (ticket to Nova Gorica) and Gorizia Centrale (ticket to Venice) have manned ticket windows.

And there is another option to go by ferry: http://www.directferries.com . Try Piran to Venezia. But of course you would have to get to Piran from Lake Bled.

We had a train problem last year, so ended up with a 4 hour layover in Villach. A charming, smallish town. We went into town, walked around, had a lunch, and back to the train station. You can get to restaurants and bars in 3-4 blocks from the Hbf in Villach.

We use www.goopti.com many times throughout the year, way cheaper than taxi and great service.

We plan to use GoOpti in a few months going the reverse from Venice to Ljubljana. We chose a shared ride based on convenience and great reviews by others on this forum.