Here are some construction tutorials

This one is from apogee and walks you through all the steps of building their torrent rocketry kit but this can be applied to most cardboard kits. The video series is a little dated with a low quality video but it has good information in it that can explain many intricate details of building a rocket that you may want to consider before buying any materials.

Another great resource is this article called How to Build a High-Powered Rocket that walks you through building a high powered rocket as the name suggests. This guide is for the HyperLOC 835 kit from LOCprecision and is a great written article on how to build a fairly advanced L1 rocket. The tutorial even says at the beginning that this rocket could easily be used as an L2 and has a electronic dual deploy. For an L1, I would recommend not getting that complicated with your rocket just yet but the actual body construction techniques are very helpful.

After getting a basic understanding of rocket construction, you will need to decide if you are going to purchase a kit, custom build or go totally scratch built. Kits are by far the most common because it ensures that all the components will work together and there are many other people who have built the exact same thing that may be able to help. If you are interested in kits, I would recommend going to the Kits page next.

If you are more of a DIY person and want to save some money by making the components yourself, or at least picking the components out for a custom rocket, scratch built is probably for you. It is more challenging but it can be much more rewarding and educational. If you plan to make many rockets, scratch built components is certainly cheaper but for one offs, kits or commercial components will end up being cheaper when you consider tooling and failed components. The scratch built page will have more information on getting started with building a custom or scratch built rocket.