Hammer Guardian ?
If you want to level up fast mobility and dmg are key. I would recommend using Greatsword – Sword/Focus. Shouts like Retreat and Save Your Self provide you with swiftness and Judges intervention with a 1200 ft teleport.
I also recommend in the lower lvls to get 2 points in honor for Superior Aria, 3 points in radiance for Renewed Justice, and at least 1 point in Virtues.
Get gear with Power/Precision, and later with Ferocity when you unlock the third stat
All these will make you lvl up fast and breeze trough events and maps. Gl.
To level up, it doesn’t really matter what you use. I suggest you to try out different weapons and see what you like the most.
Do you still ask for leveling up? If yes, the answer is always the same. Take that time to experiment and use the weapons you prefer. You lack trait, runes, gear, sigils, etc so it’s not like you will be a force to be reckon with in WvW that you have the best weapons or not. Trying different weapons, will be more important while leveling your profession. Once you are level 80, then you could look for what are the best options.
PvE
GS + Sw/F : Best overall set. Give you high dps and a lot of blind
Sceptre/Focus : Best dps but only against large/slow target. It’s also a good secondary set if you need to range stuff.
Hammer : About 5-10% less dps than GS + Sw/F, it give perma protection to your team
Mace/Focus : Use it with either an Hammer or a GS. It’s a couple percent less dps than sword, but give a bit of sustain.
Torch : Can replace Focus. Less good, but not a totally bad choice either. It give you access to more fire, if you need it to activate Fiery Wrath (trait).
WvW Zerg
GS : A good mobility and large cleave against zergs
Hammer : A bit less dps than GS, but give you access to blast and immobilize
Staff : Switfness, CC, healing, large Tagging machine, might. It’s one of the favorite weapons for a Guardian in WvW.
WvW Roaming
I don’t roam with my guardian. But GS, Sw/Focus, Sceptre/Focus are usually good choice.
For levelling as stated above GS with Sw/Focus is best. When i levelled my guard i tried all the weapons but what i liked most was GS/Hammer. Hammer is awesome in PVE Events and i just love the skills on that weapon.
Staff/Hammer for WvW is meta but even there i tend to run mostly GS/Hammer or GS Scepter/Focus for my style of play.
“Buff my main class, nerf everything else. "