I’m a single adopter. Finances can be tricky.
How much savings you should have depends on your outgoings and how you are funding your adoption leave. If my mortgage is £600 a month and yours is £300 then you would less savings than I would for example. I only had a few thousand in savings because I had a great adoption leave package.
I would work backwards from your outgoings, set a budget for what you need to live, look at what you will get from adoption pay and that should give you a figure to aim for. Not having debt, apart from say a mortgage/car loan, is as important as having savings.
Benefits are a difficult area. The only one you are guaranteed is child benefit which is £80 a month so not much. I don’t know how universal credit works I’m afraid but you may qualify for some. I do get some tax credits which are enhanced because my son is in receipt of Disability Allowance. If you rent then you may get the housing benefit element of universal credit. Some local authorities give adoption allowances but these are rare and entirely discretionary - you would probably only get one now if you adopt a child with significant needs or a sibling group.
My advice is if you can, try and arrange your finances so that you are not reliant on benefits, they don’t give you a good standard of living and you can lose them.
I do receive some benefits but I’m not reliant on them, I’ve had to make a lot of adjustments in the last year or so as I’m not convinced that he will qualify for PIP (what you get at 16 instead of DLA). If he doesnt get PIP, I will lose the tax credits - its a big hole in my finances, I’ve increased my hours at work, saved a bit and fortunately I’ve only got 18 months left on my mortagage so we will be OK but may have a very tight 6 months next year.
My family are not local to us so not much use on a practical level, they think my son is the bees knees and make it up in other ways. It wasnt a problem for assessment. Think about different scenarios - who could help if you were ill, what would happen if fell over and broke a leg, needed a hospital stay, babysit, do an emergency pick up from school.
Its also good to show that you are open to new friendships and will seek out support