Learning to read, write and speak in Russian...?
I think this site is pretty good http://www.russian-language-for-lovers.c... It's free, and it's for lovers! :)
What language should I learn Mandarin or Russian?
Running contrary to the advice of Dashgr, I don't think you should try and learn Mandarin and Russian at the same time. If this is your first foreign language, motivation will be key and the relatedness of the two langauges will not matter as much as you burning out and just giving up due to difficulty. Trust me, this is coming from personal experience. Focus on *one* language until you reach at least a conversational level. "Only" 250 million? 250 million is quite a lot, especially when you consider the number of people in Central Asia, Ukraine, Belarus and the Caucasus that use it as their primary second language. It can also help give you a basic understanding of other Slavic languages (non-Russian Slavic languages having something like 200 million speakers taken together). Learning a language is a massive undertaking, especially if you're doing it as a hobby and are not immersed in it. For that reason, I'd suggest the one you're most interested in. As you want to learn Russian, go for Russian. Tell your father to learn Mandarin himself if he's so keen on it. Mandarin (or any language, really) is hard enough even if you do have a personal interest in it. Furthermore, the US government (I assume your American?) requires skills in dozens of languages (including both Mandarin and Russian, as well as languages with less than 100 million speakers like Yoruba and Pashto) so I don't think it'd be a bad carreer move to learn Russian.
Should i learn to speak German or Russian?
I would say learning Russian is harder than learning German. However, a lot of people are put off by the Cyrillic alphabet used in Russian, when they really do not need to be! Once you've got to grips with it, which could take as little as a day or two, there's nothing stopping you! I will not recommend a certain language because no one language is better than the other. You need to think to yourself this, "which will be more useful to learn?" in other words, which will you use more once having learnt it.
Should I learn Russian, Modern Greek, or Spanish?
I already know a teeny tiny bit of Modern Greek, and some Spanish, but I also want to learn Russian, Italian, German, maybe French. The problem is, I can't decide which to learn first. I'm still learning basic Modern Greek, so after I finish that I want to go onto a different language, but I don't... Right now at the moment I want to learn Modern Greek, Russian, and Spanish, but I keep moving from one to the other; I don't know which to learn first. Should I try to advance in Greek first before Spanish, should I drop Greek and learn Spanish first, ect. But if I did that, I'd feel like a loser, since my dad said I couldn't do it. Since half of my family is Hispanic, they want me to learn Spanish- they're practically forcing me to. I'm very interested in the Greek and Russian cultures, so I want to learn them, and if I learn Spanish, it should be pretty easy to learn the other Romance languages. I know Greek is impractical to learn, but I'm interested in it, and want to go to Greece some day... I'm only 14. What should I do??