which civilization?
U can find here at forum sites some good civs for 60f11 see krombacher civs.
- what to do at start?
(Is for 4v4 islands 60f11)
Start is all about booming fast as possible till you reach first worldwar age. Depending on your skills that needs average 130f11 maybe 30min. Of course u could attack earlier right after 60f11 but it isnt common in games from expertplayers. ( means not allowed

)
Briefly i can say make 6 cits at preage.
At stoneage u go fishing till ~25-30f11 while u makeing constanly new citiziens and populate some settlements near gold and ironmines.
At coperage u make farms as much as possible going bronce when have enough ressource.
At bronce and premid u just make further farms till u got 11
At mid u fill up your mines and build two either Alexandria and ischtak when u play as wing or alexandria and lighthouse as a pocket player
Till yet u have 11 farms and all mines filled up u can just go up to the next age and dont have to do any further things on booming.
- which epoch is reachable at F11 60 (depending on standard or tournament game variant)?
ending epoche dont depend on which variant u play ( but it is common to set ending epoche to nano)
- which pop is reachable at F11 60 (citizens/military)?
u got 192 free population when u have developed all updates in ur hosiptal ( at 4v4 game)
- which kind of military unit is the most appropriate (ship, air, land...)?
of course depend on many things like enemy, teammates or position u play ( wing or pocket), but one can say for wing it is siege, subs and tridonts, for pocket is air
- how to organize the defense?
Of course depend again on enemy no need to make any defensive vs clear weak opponent. but in general one can say as wing u have to make many antiair on your island, make a prophet in case opponents start bulidng ships, make stormcyborgs and use them as another way to defend your island from air attacks. As pocket usually u just make fighters which defend all wonders from your own team, u should make use of apoll and storm too.
As u can see defending is mostly against air.
- what is the best way to attack?
ok another strategy question. i could more in detial but that doesnt make any sense due to your skillevel. But in general as wingplayer u should get navy between your island and those from your opponent consisting of subs tridonts and antiairships but before u can do this u need to make a lot of siege to prevent your opponent to to do the same. As pocketplayer u mainly just bomb in a way it hurts ur opponents most, u can bomb wing but of course u might do sometimes a attack on opponent pocket and try to destroy some of their wonders.