Oh, you're in for Fun times. I've never had migrant waves of 71 dwarfs, especially not in the second year. It looks like the RNG has blessed you with a special challenge. It'll be a lot of work, but if you make it through the next year, you are truly worthy of Dwarf Fortress. (And if not, hey, Losing is Fun).
Your priorities right now are food and bedding. Divide the migrants into groups: you'll need a lot of plant gatherers and fishers. Clear the map of bushes. At the same time, you'll need a lot of storage space. Dig some large storage halls and fill them with food stockpiles. Rotting food is not something you want right now.
For additional storage, mass-produce rock pots. You'll need maybe 5 stone crafters working on repeat, each in their own workshop. It'll go faster if you set a stone stockpile next to the craftsdwarf workshops and use some wheelbarrows for hauling the stone, that's optional though.
Don't cook anything right now, that's a waste of food. Your bottleneck is going to be booze. Even if you get some additional brewers, the migrants will probably have to drink water for a while because if you brew too much, there won't be enough food.
The fisher dwarfs will get you a constant income of fish (if there is any on your map), but to be sustainable, you'll need more farm plots. You'll probably lack the seeds to expand the underground fields, but the plant gathering should get you a lot of above ground seeds. You'll have less protection there, but it's just a temporary measure, and starvation is a more urgent problem than external attacks. You'll need maybe 10 to 15 dedicated growers for planting the seeds. In the orders menu (o), you should turn on "Dwarves all harvest" (h) to speed things up.
It would be best to divide your population so you can do all these things at the same time. That's a lot of management, but it'll pay off.
And while you're doing this, see if some migrants brought axes. They'll all become woodcutters. You'll need a lot of wood for beds (maybe hire a few more carpenters), about 30 should be good enough for a sufficient communal bedroom because they don't all sleep at the same time. If you have any wood left, make it into barrels for more food and booze storage.
Good luck, you'll need it. Have fun.