Roleplaying a wizard at level 1 that plans to be a bladesinger

[Rezby]

You don't just up and start bladesinging one day, it's something that gets passed down, aka you write into your backstory. But for a campaign that starts at level 1, what do you do? Do you take the easy way out of "oh yeah character just hasn't quite mastered the specific techniques involved yet" but otherwise write it into their backstory?

[DivisibleByZero]

Just consider yourself "in training" for the first level.
A boxer doesn't one day decide to box, and the next day has a match set up. He trains in his down/off time until he's ready to enter the ring.
Those first level, you're training. Level two dings, and you're ready to enter the ring.
It's also similar because when you *think* you're ready to enter the ring, you're extremely likely to get your behind handed to you for a while, just like a new boxer.

[Princess]

This is way easier to do with an elf character, if you're playing a classic bladesinger. You already have shortsword proficiency, and could take the shield spell, so you start out more combat capable than other wizards.

[Klorox]

This is way easier to do with an elf character, if you're playing a classic bladesinger. You already have shortsword proficiency, and could take the shield spell, so you start out more combat capable than other wizards.

This. Or, work it out with your DM that you're traveling for your ancestral rapier (or whatever), and your friends are helping you on this relatively easy journey.

You get it at level 2.

[Sir cryosin]

Remember you don't need prof in a weapon to use a weapon. You just don't add your Prof bonuse to the attack roll.

[Biggstick]

Who says you're not already a Bladesinger? Although in character you haven't performed a Bladesong, maybe you've gotten pretty darn close to it before joining the party. This journey or leaving of your trainer is a way for you to go off on your own and finally learn what it means to sing your Bladesong.

You can easily do this, it just requires a bit more work with your backstory.

As for the party. you don't have to really tell them much of anything. As far as they know, you are what you tell them you are. You don't have to prove anything to them (as far as I know). And if they're dead set on you showing something to them, stick to the fact that you're still a Wizard who is just as competent at Wizardin' as you can be expected to be.