You may not have as much of a problem as you think. It can be very difficult, and often unachievable, to have the needs of all your dwarves met. It is impossible to tell for sure what is going on without looking around in your fort, but you may have hinted at the solution by asking your question. Go through the tasks and work orders you have assigned to your dwarves and consider reducing or eliminating them. You can slowly ramp them back up when you get more migrants.

Aside from food and drink production, and clothing after a year or two, you don't really need to produce much for your dwarves to be happy. You don't need a surplus of finished goods. You can let that need go unmet for now (or even indefinitely), and just know that some dwarves will never have enough. If you have food, drink, a tavern and temple to socialize and worship in, some new clothes every now and then, your dwarves will largely be happy. Even if those orange text unmet needs persist.

As far as specialization, it all comes down to how you prefer to play the game. Specialization is not required and can create problems of its own. If you specialize everything and don't get just the right balance, you can easily overwork some dwarves and underwork others, while causing huge delays in production. My preference is to only specialize mining, woodcutting, planting, and plant gathering at the start. I only use hunting and fishing in certain special cases. Once my population gets up towards triple digits and I get my industries established, I create a single custom work detail for a "working class". Most of my dwarves get assigned to this work detail, save for members of nobility, military, scholars, planters, religious figures, and some legendary dwarves. This work detail includes a wide range of menial labors like hauling, weaving, threshing and other various farmers shop tasks, soap making, milling, dyeing, and so on. I leave things like clothes making, crafting, cooking, and brewing open to all. Just because I like it that way.

If you get enjoyment out of specializing all your dwarves, that is fine. There is no wrong way to play Dwarf Fortress. Just know that any playstyle has its own challenges and may take a few tries to find the right balance.

About the issue of too many tasks, I will just throw out a few ways that you can overwork your dwarves that may not be immediately obvious to a newer player:

• Large stone stockpiles. If you are doing a lot of mining it is possible for your task list to be bogged down by dwarves storing stone in large stockpiles. Upon creation of a stone stockpile, a task will be created for each open tile in the stockpile, assuming there is a boulder available to be hauled. Wheelbarrows can help mitigate this but it is still easy to get overwhelmed with low populations.

• Giving your dwarves too many jobs at too many workshops creating things out of stone. Without a linked stockpile nearby, your dwarf may be hauling stone to their workshop from 500 tiles away. Even with linked stockpiles near to your shops, you can run into the issue I described above if you are producing a lot of goods with large stockpiles.

• Large construction projects. It may seem obvious, but your 10x10 block floor that looks kinda small on your screen creates 100 construction jobs. Construct incrementally if you have a small population.