So, unfortunately with the character class you have you aren't proficient martial weapons which is what a longsword is. If you check out the equipment in the rulebook, you can switch to any simple weapon, which you I believe you do have a proficiency in.
You can always use a weapon you're not proficient in, but it would result in a negative modifier to attack rolls.
Also, as far as you're weave affinity is concerned: women generally dont have an affinity for fire. That doesnt mean you cant use weaves with fire, you just dont get the bonus.
I tried to give you weaves that pertained to protecting or aiding, as that was what you had expressed earlier. If you want to check out the other weaves that are available you can find them in the rulebook or if you have trouble with that, I can list the ones you'd be able to use.
Bromern Sal A Shadow RDI Staff Karma: 142/11 3754 Posts
Simple weapons would be staff, club, dagger... things that you wouldn't need any formal training to use. Generally speaking, magic-users aren't allowed martial weapons because they spend their time studying magic whereas warriors would spend their time studying swordplay.