Just to add a few notes:
The only things you really need to buy/obtain are in game. As others have mentioned, you can buy the skill unlock packs, but these aren't directly usable:
Let's say you buy all skill unlock packs. You decide to start up a new ranger character in the factions campaign. You open up your skill panel, ready to see all the 140 ranger-specific skills that you've just spent your money on. Instead, you're met with a nearly-blank page. This is because the skill unlock packs only unlock skills for pvp chars. To get them on a PvE char, you'd need to use something called a skill tome (available for purchase from other players in game, with in-game money). As such, it's probly a waste of money for you at this time to buy the skill packs. Instead, just play through the game as much as you can.
As far as talking to NPCs, be aware that nearly every NPC in Guild Wars has some sort of written dialogue. However, not every NPC says something you need to read. If an NPC is going to give you a quest, you'll see a green, floating arrow pointing down above that person's head. They'll give you a long speech on how you need to save Mr. Fluffy or something, and then there'll be some version of an accept (Check) and reject ("no" symbol) button. Once you accept the quest, it appears in your Quest Log (press "L"). Quests in the log are then organized by the area in which you got them, or their priority: Primary or Secondary. Primary quests advance the storyline, get you from Mission to Mission, and often cannot be abandoned. When in doubt, follow a primary quest. Secondary quests are optional, can give you side-rewards (including skills!), can be abandoned, and will lead you oft astray.
The only other thing that you will need to buy at some point is armor (again, in game). This is because at a certain point in the game, starter armor just simply won't offer enough protection to keep you alive. If you don't want sad monks, you'll get higher armor for better protection (happy monks = good).
You also mention talking and no one responding. A quick note: down near the bottom of your screen, on the left hand side, there's a little series of checkboxes. They should be, in order: Local, Guild, Team, Trade, Alliance, Whisper. Make sure they ALL have checks in them. If they do, it may very well be that no one is talking. People often tend to go on about their business in GW. If you're in a quieter town, you may just not encounter anyone who's really willing to socialize.
As for pets, you cannot buy them. As a ranger (primary or secondary profession), you "charm" pets that you find outside using a skill ("Charm Animal"). Once the pet is charmed, it becomes yours. You can rename it, force it to participate in fights, exploit its corpse, and generally do all sorts of things that the SPCA would be horrified at. There are things called minipets, which are little dolls that follow you around and don't fight/interact in any way, but these aren't going to help you. If anyone says "selling pets", they're either scamming, misinformed, or they're selling these minipets (which, again, you should NOT buy). To clarify: if you're not a ranger primary or secondary, you cannot actively have a pet.
