The quality of cider is down to the quality of the ingredients that goes into it. Using Lidl juice for cider making is really coming in at the bottom end. Yes you'll make a cider and with some work it can be adequate. For the best ciders you need a blend of decent apples with some sweet (40%), some sour(40%) and, if possible, some bitter(20%).
Most juice in cartons would be on the sweet side with only a little sour. This leaves the ciders a bit thin and bodiless. Some people add mushed up cooking apples, but this is not that great as the mush does not easily let go of its juice unless pressed (otherwise ciders makers wouldn't bother pressing at all).
If you're going to use lidl juice, I'd add 200g of unsulphited raisins to the demijohn (unsulphited is important as the sulphites kill your yeast). Some people add tea instead (a cupful of strong black brew is commonly used). These additions will add tannin to the juice which can benefit the overall mouthfeel and preceived body.
When bottling I'd do a taste test and, if too sharp, I'd add Splenda (or lactose if artifical sweeteners are not your thing). If you're going for a sparkling cider, this sweetenner would be in addition to the sugar your adding as priming sugar.
When it comes to drinking time, the lidl cider will sometimes still end up a bit sharp. If so you can add some apple juice as a back sweetener and as a body improver.
Irrespective of the apples used, or the juice used, no cider is worth drinking until at least three months have passed since fermentation began. Maybe more. I'm not ready to bottle my own and it was pressed in Novemeber. Maybe in another month. Maybe in another three.
/J