A lot of this depends on size but something that doesn’t is that you shouldn’t put your scars in the sun at all.
Most girls seem to have dropped by 6 weeks, but not completely, they may still look a bit fake, but that depends on size.
Your scar will probably be in the crease or slightly above so a string bikini should be OK but if i were you i’d go for something a bit more supportive, even a string with a wider band at the bottom.
You should be able to go braless, but again depends on the size you are having, some girls are advised never to go braless.
Wish i was going on holiday soon!!