Bikes come 90% assembled. It will take about 10-30 mins to assemble the rest of the bike. If you want someone to assemble, any shop can do the assembly in about 50 euros . We however advise to self assemble because it's too easy.
Videos of assembly bikes can be found easily on YouTube just search for "bike name" unboxing.You can check them before buying. Reach out if you have further questions