Hello and welcome from Carnoustie
This is our second smallholding - first was an acre, this one is 12. Neither were smallholdings before we bought them, so we've been where you are. If you have a spare hour or so, have a read at the diary on the website - it charts our progress since 2000. There are also articles, based on our experiences, that might help as well.
And of course, this wonderful forum where lots of folk will be able to help.
I agree with FW and suziequeue, take your time, start small and work up. We started with the vegetable garden and three hens, then a couple of weaners, then a small orchard and more hens, then a few sheep. This was over seven years.
Since we moved here in May 2010, we've put in a veg garden, fruit garden, gone up to 60 hens, planted 60 apple trees, expanded the sheep flock a wee bit and bought two Shetland heifers and a bullock. We have three weaner pigs this year for the first time since 2009. By the end of this year, we should have the infrastructure in place, then we'll be consolidating the various enterprises. Sometimes it's important to decide what you're NOT going to do - like, we won't breed pigs, keep goats, waterfowl or turkeys
Good luck with whatever you decide - sounds like a wonderful challenge