You can first set out the template on the ground with the arched beam, then add the anchor bolt according to the setting out, gradually lean the angle iron against the anchor bolt, weld it firmly, and then hang it to the roof with the beam. 14m is less than 4m and a half wide. It is safer to add a section of angle steel beam, which means four beams are needed. Then, the middle part should be fixed with cross braces to increase stability.
If necessary, you can contact me, and I can provide you with three-dimensional renderings and details of consumables to ensure that you can finish quickly and save money. The consumption of paint will certainly give you a budget.
Good luck.