first of all ... welcome to the BWB
second, I agree with all of what Cykill says ...
your gimmick is something you gotta come with on your own, but I would play off your name ... Liberty ... the freedom fighter ... kinda like a one man Justice League ... your motto could be something along the lines of ...
"Be not afraid citizens ... for when there is injustice there shall also be me,
Factor of Libertas, the defender of FREEDON and the enforcer of LIBERTY"
(I get a picture in my head of Adam West (Batman from the 1960's TV show ... he also does the voice over for "Catman" on the Nickelodeon Cartoon "Fairly Odd Parents") doing the voice over for this ... very campy ... but can be played out to perfection with a little practice)
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for RP advice ... consult the following articles
WIKIHOW ... page 1WIKIHOW ... page 2Bright Hub ... has a nice article called the Do's and Don'ts of Role Playingthat should get you started on the right track ... if all else fails, go read some of the others posts here (actually read them , not just skim over them, to get a feel for how others do it)
another place you could try is the Federation page itself on TWG ... look at some of the other shows and see how they do things
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just remember, the more you do it, the easier it becomes. Just remember to start small and work up from there