Lining paper and gloss paint

It is more advantageous to gloss first, allow the paint to dry and then apply the paper. This reduces the chance of paint getting onto the paper.

Do the lining paper first allowing to dry out properly before applying paint to paper, then gloss woodwork last

Hang and paint the lining paper first. But a plan while prepping the walls for the lining paper, would be to prep the skirting boards at the same time, and even apply a coat of water based primer/ undercoat to them

My personal method, to make it a neat and tidy finish, would be. 1) Prep walls and skirting. 2) Hang the lining paper. 3) Prime/undercoat the skirting boards and bring the paint up onto the lining paper a couple of mm. 4)Caulk the top of the skirting board to fill any gaps and give a neat join. Assuming you trimmed the lining paper correctly you can over-lap the caulk onto the paper to hide the egdes. 5) Put your top coats on the skirting boards and let it dry properly. 6) Use a low-tack precision masking tape and mask the skirting, bringing the tap just a little bit up onto the walls. 7) Paint the walls 8) After your top coat is done on the walls, carefully remove the masking tape. All being well, you will now have a lovely straight line and no sign of lining paper at the bottom.