Completely novice gardener needs advice on pruning

[Eutectic1]

Hey,
I'm new to both Mumsnet and to gardening!
I've just moved into a new flat and for the first time I have outside space - very exciting!
I'm pretty sure there is a jasmine plant in a pot climbing up one of the walls of the house, but it is looking a bit sad. Mostly woody stems (the longest perhaps 10ft??) and not many leaves. Some of the shorter stems seems to have a bit of new growth which is encouraging.
I've seen some houses nearby with beautifully bushy looking jasmines.
My question is... do I need to prune it to get more growth next year? How much should I take off? When should I do it? Can I kill it by pruning too much?
Thanks for your help and I'm sure I will be bothering you all with more novice questions as I find out more interesting things in the garden.
E x

[Phalenopsis]

When to prune it depends on when it flowers. If it's summer pruning, it's best to prune after flowering late summer/autumn. If it's winter jasmine then it should be pruned in spring again after flowering.

To prune remove weak (thin) side shoots and cut to a strong bud lower down on the plant. This will encourage new bushier growth. It sounds from your description that the previous owner has left it and it has become leggy. Also prune out any diseased looking growth.

[Ferguson]

MNers can help a bit on all sorts of things, but if you want more guidance, there may be dedicated jasmine sites or groups (just guessing), or also try RHS and BBC Gardeners World for all things horticultural.