SILIŅI. I need gardeners advice. Planing out our territory.

Winter is the time when to plan what to do in the future/spring/summer. So I decided to finally put on paper what I had in my head for all this time. I already contacted Sean Dembrosky from Edible Acres. I've been watching his videos on YT for a long time. But I would like hear some other people opinions on this topic as well. So if you're a gardener/homesteader or simple have any valuable information - please leave it in the comments. Or shear it with your friends.

Our territory is about 0.6313 ha = 1.5567 acres, and I divided it into 5 smaller areas. And today we will be looking at the first one. It's about 16x24 meters / 52x78 feet.

Our property is right next to the road and for many years there where growing lilacs. It worked as a fence. They where really old and overgrown. I cut them down and we pulled out most of the stumps / roots, but still, there are some roots in the ground and new shoots are coming out. My uncle wanted to give me roundup to kill them off, but we said NO. I rather pull them out one by one with my hands. And that's what I did - you can still see a pile of roots that I dig out. My plan was to plant [starting from the north] in row's Spruce's [to give us some wind [we live quite close to the Gulf of Riga and northen winds can be quite rough] and noise [the main road is just some 20 /30 meters away] protection, and they could work as a fence as well], then some apples / cherry / pear [depending which ones go better together with the given environment] and then black currant/gooseberries and a litlle bit of quince. I divided the area into some smaller zones. I don't know how much space every individual plant needs - the measures are quite rough. I guess it's around 3 meters = 9 feet for trees and 1,5 meters = 5 feet of berry bushes.

As I wrote before, we have some pretty bad soil - it's basically sand. My plan was to bury a lot of old / rotten logs from the forest [we have a piece of forest - rotten trees is not a proplem] and plant stuff on top of them - I guess it's called hugel method. At first, I had an idea that they could rise a little bit above ground level [that way it would be easier to pick berries], but then I had doubt's about keeping them moist. If they are above ground all water is going to run off. So I think everything is going to be ground level.
I talked to a local lumber mill and I could get some sawdust from them. I could use it later on together with leaf compost to keep the soil nutritional rich. And since we live close to the "sea" - in autumn we can get a lot of seaweed. I think that should do the trick.

Some specific questions that I have problems with:
How much space does spruce / apples / berries need? [I guess it's around 3 meters = 9 feet for trees and 1,5 meters = 5 feet for berries]
How much sun do they need? Do they need any shade at all? [It's an open area and there is no shade - I guess that's good]
Does any old rotting tree work for the hugel method? Which ones are better? Should I avoid any species? What about Ph levels? - some friend told me that these trees might not work because the Ph level in the forest is different. [I don't think it's that bad - I'm not taking home peat it self]

This is my initial plan. I already brought home from the forest some old logs that I plan to bury when the snow melts and then plant some blackcurrant on top of them. I still need to find some info and place where to buy gooseberry plants, and raise some money for it as well. I'm planning to make wine out of them so I need to figure which ones are going to suit me better.