The main thing he did was watch over <PERSON>. That was his main purpose there, as he said to <PERSON> and <PERSON> on Polis Massa. <PERSON> says "To <PERSON>, to his family, take him.", and <PERSON> says "I will take the boy and watch over him." There are many instances in the legends where he 'saves' <PERSON> from skirmishes, etc. eventhough <PERSON>'s Uncle <PERSON> wasn't too happy about that.
With regards to his own life, he continued with his training, despite not having a master with him. As <PERSON> says to <PERSON> on Polis Massa, <PERSON> old master <PERSON> had contacted him and had found the way to 'come back' to the world of the living and interact with people. <PERSON> had not completed his own training, so he could only come back as a voice (I think), but he told <PERSON> how to do it. <PERSON> taught <PERSON>, and he spent at least some time on Tatooine training with this particular 'power'.
This last part is just speculation, but he might also have travelled at least around the immediate vicinity of where he lived and where <PERSON> lived, and got to know a bit more about the planet he was on. Evidenced by:
* He knew a deal more about sandpeople than <PERSON>, though <PERSON> had been living there as long as <PERSON>. When <PERSON><PERSON><PERSON> and <PERSON> found the butchered bodies of the Jawas who found C3PO and R2D2, <PERSON> suggested it might have been the sandpeople who attacked them. But <PERSON> says that the blaster marks on the Sandcrawler were too accurate for sandpeople, and guessed correctly that it had been Imperial Troopers who killed the <PERSON>. He probably interacted wth the sandpeople enough to know how well they shot. 605
When he saved <PERSON> from them, he also knew how to scare them off.
* He was familiar with the denizens of Mos Eisley. While <PERSON> did mention the town in the movie, when they actually went there, it was <PERSON> who somehow knew exactly how and where to find a smuggler. If he'd simply found a passenger ship, this could be waved off. I'm sure many people would want to leave Tatooine, and would not need to do it so hush-hush, so a simple cruise ship would be what most travellers look for. But <PERSON> found a smuggler of all things, and normal people who are unfamiliar with the place would not be able to find one that easily.
* He also knew <PERSON>. While in Episode 3, we see that <PERSON> formerly knew <PERSON> and helped him escape Kashyyyk after nearly being killed, we also see that <PERSON> remained on the planet, and did not follow <PERSON> to Polis Massa. So, since that is the only moment before Episode 4 where <PERSON> appears, and he does not meet <PERSON> then, it only makes sense that <PERSON> only met <PERSON> after he started living on Tatooine.
EDIT: From the wikia, the cantina on Mos Eisley was indeed a popular gathering place for spacers, smugglers, and the centre of a host of criminal activity in Mos Eisley. So you could argue that <PERSON> might have simply heard about the place, brought <PERSON> there, and met <PERSON> by chance. But to have asked around for smugglers who were willing to evade Imperial Troopers would have attracted too many unwanted questions and rumours. There was a very high chance that some smuggler could have rejected them, and then tattled to the Imperials for money, if <PERSON> had simply walked in without a plan. In fact, someone did tattle to the Troopers just before the Millenium Falcon took off. 865