@Archangel Hmmm, in that case...
Assuming you're going for the normal race restrictions on that, you're probably using a High Elf for the +1 INT and +2 DEX (or a human or half-elf with DM permission, but imma use elf as my example here).
In order to have Bladesinging from the start, you'd need 2 wizard levels, so it'd be Fighter 1/Wizard 2. In that case, it really depends on which starting saving throws you want to have that'll determine which class is taken first. It could go either way. Fighter gives CON save prof, which is amazing on casters, but INT and WIS saves have their place and the Bladesong wizard feature already grants a big INT bonus on CON saves to maintain spells. But I'm digressing.
In that scenario, you can use only Light armor to get the most out of your Bladesong, and any one-handed melee weapon is yours to choose. (one-handed tends to be the big limit to Bladesong).
Then, as an example, a Rapier would be your most ideal weapon, since it uses DEX and does a 1d8 dmg.
If we plug High Elf race in and redistribute 1 point from INT to CON, then we have...
STR - 8
DEX - 20
CON - 14
INT - 18
WIS - 10
CHA - 8
HP: 20 (taking average hp)
AC: 16 (light armor)/ 20 (with Bladesong)
+7 to hit with Rapier, +5 to damage.
I don't know what kind of Fighter fighting style you're running, but I imagine for this build it would be either Dueling (to make your one-handed weapon a nutty +7 to damage) or Defense (for +1 AC for a total of 17/21, since you assumedly have leather armor in this scenario).
Of course, all this is assuming you aren't leaning harder into the Fighter armor for AC instead of using DEX, but that is quite frankly, very incompatible with a Bladesinger Wizard.
I guess what I'm trying to say is STR is a... less than ideal stat on your proposed build. If you're worried about saves, you could maybe drop DEX to 18 and up STR to 9 (for carrying capacity, if nothing else) & CON to 16, but other than that...
Naturally, however, at the end of the day, this is merely the more min-maxed example of your PC concept. Don't let me tell you how to build it. If you have a specific character concept in mind, go for with all your heart and play what you like. At the end of the day, it's most important that you're enjoying yourself.