Revivng slumbering motorcycle

If your fiberglass tank is leaking, REPLACE IT. It's not worth a burnt down bike.

In this order:
remove carbs as a whole, disassemble individual carbs while leaving the bodies together as a bank (if so configured), clean paying attention to idle circuits. This means removing all jets AND adjustment needles and spraying until carb cleaner flows freely. Replace any cracked vacuum caps with OE stuff, not parts-store garbage. Be careful that carb cleaner doesn't come out some other passage and spray you in the eye or the crotch. Remember, there's NO need to break the carbs apart from one another. You're just cleaning passages. Dumping carb cleaner in the carbs on the bike will NOT cut it.

Don't bother synching the carbs unless you disturb the adjusters between them, and you need to run the valves before synching anyway.

Drain the oil, leave the filter, and replace with motorcycle oil. It needs to have friction modifiers for the clutches.

Add fuel to system, and supply vacuum to fuel valve/petcock as required to start fuel flow. If it leaks, STOP NOW and fix the leak.

If points, inspect for corrosion and verify gap but don't adjust.

Add hot battery, and NEW spark plugs. No jumper cables. Hook it up right.

Fire it up, run it long enough to get it hot via idling, and then change oil AND filter.

Now, and this is important:
GET NEW TIRES before you ride it. They're going to be rock-hard and GREASY. This thing will be a death trap until you do this, so don't ruin your new-ish bike and possibly you in some crappy dammit accident.

Have fun!