What's the worst that can happen to you ...
As long as you can get over that you can't jump in gw1, you'll probably enjoy this game. :P
But as long as I'm on the subject, I'd like to just elaborate more on a few subjects that have already been mentioned.
1. PvP. The game is built around it. Back in the day, every skillchange (up untill a certain point post-nightfall, where they implented pve & pvp versions of the same skills) was based upon the pvp balance. If certain skills were too good in pvp, they usually got nerfed or changed. You even have an option to just skip pve and just make a max level pvp toon and jump right into the action.
2. The skills. Every profession has access to about 150 skill. But everyone has an option to choose secondary profession at will and to no cost (once unlocked), thus unlocking another set of 150 skill. And the fact that you can choose from any of the 10 professions, you'll have plenty of skill to choose from. The limitation of only being able to use 8 at the time, that's including only 1 elite skill, will make sure you spend your time prefecting your skillbar. Luckly there's an option to save your current skillbar & skillpoints, and even to share/copy them from others. You'll quickly find tho, there are a few skillbars that seem to be the meta at any given time. Back when I started gw1 ie: pvp was dominated by IWAY-warriors and bunnythumper rangers. Pve was mostly minionmaster necros and elementalists. Every month skillchanges gave birth to new builds, so things never really got stale.
3. The skillz. With access to a huge skill library at any given time, the selection prosess for both pvp and pve content can be confusing, and possibly decide if you fail or succeed. Every class and skill has a counter. If your up against alot of melee's and rangers, you could opt to choose more skills that blind or mesmer/necro hexes that damage when the enemy when they use a melee attacks or autoattacks. If your facing more casters and especially healers, you'll need more interupts and anti-spellcaster spells like diversion and backfire. And so on. And you'll also have more success if you can dodge, kite and stay out of the fire also, but that goes for most games I reckon.
4. PvE. You can decide how you want to play. Most people these days just solo most things with heroes. But you can if you choose group up with other real players or if you choose solo the content without heroes or henchmen. For most missions though, you'll just hero/hench it. For the later end-game instances like underworld, fissure of woe, or domain of anguish (there are more buy I cba to name all.) you'll want a full group of real people to clear the content as fast as possible. You can of course go with heroes, but you'll take more time and have a harder time at it.