Vilnius is great. The university is pretty decent. If you're sociable and outgoing, I think you'll do well. I think you might have a little bit of trouble learning Lithuanian here if you don't make a conscious effort to put yourself in situations where you'll be required to speak Lithuanian as nearly everyone under the age of 40 in Vilnius speaks decent to really good English and they like doing it. And that's saying nothing of the English slang that has pervaded (/is pervading) the Lithuanian language itself. I probably don't need to tell a linguist this, but Lithuanian is no harder to learn than any other similarly dissimilar (hah) language. It'll be more difficult than Portuguese or any other Romance/Germanic language, the cases and genders will piss you off, as will some of the pronunciation. Exercise your tongue and you'll be alright! Step 1 is getting trills down, then – don't aspirate your plosives and, last but by no means least, learn to palatalise those pesky consonants. Lithuanian is said to have more or less free word order but that's not strictly true. Almost any word (or syntactic unit) can go anywhere, but the emphasis this creates can sound odd in neutral sentences. As for your book – it's from 1966. I have never heard of it so I can't attest to its quality but I'd be wary of it being a tad outdated. While Lithuanian is a pretty conservative language and not all that much that has changed phonetically/phonologically/syntactically since then, the spoken language is a different kettle of fish. The classic advice for anyone learning a language is – try and find opportunities to use and hear the language in genuine and meaningful contexts. I think TV is a good way to do that but Lithuanian TV isn't very good. I have, however, heard good things about a web series called "Online Serialas", which you can find on YouTube. I don't know of any non-Lithuanians on this subreddit that have lived here and learned the language but I do know of at least three or four in real life. I also know a few that have been living here for +/- 5 years and have learned only a few phrases. Lithuanian in Vilnius isn't a necessity. There's an English musician called Mark Splinter who speaks pretty good Lithuanian and there's videos of him on YT, he's also pretty active on Facebook, it might be interesting to check him out.