We can say that Surabaya is the heart of east Java. It is the capital of East Java province, but Surabaya is more than that. So, no need to wonder why this city is crowded by tourists. By train, it took about 4 hours from Yogyakarta. We left for Surabaya in the morning and it's noon by the time we arrived there, via Gubeng railway station. Gubeng is one of the entry to Surabaya. n Gubeng railway station, there's a map that you will know easily where your destination is. Or you can get here via Juanda International Airport in South Surabaya.
This city has so many tourist destination. Beach, Museum, Mall, Mosque, etc. Need a cheap shelter? We found some backpackers hotel with reasonable rate. Gubeng Hotel charges you IDR 90,000 while Sparkling Backpacker Hotel charges you IDR 115,000. The cheapest rate in City Hub hotel IDR 250,000. They are surely recommended. If you're crazy enough, try to sleep in some public areas like a station, mosque, or (maybe) the sidewalk.
Just so you know, Surabaya is friendly to all backpackers. We simply loved the sidewalk. Unlike other cities in Indonesia, Surabaya's sidewalk is street vendor-free. You can wander around all day long then. This city also has numerous public transportation and taxi is the best. There's no reason to postpone your plan to go to Surabaya. Why don't you just pack now and "strike" Surabaya!