As a first time builder, I think that the most important piece of advice that I can suggest is to try to find a 'mentor' - someone who will work with you at least for the first few steps. A mentor can help you attain an acceptable level of work completed, which tools to purchase and importantly, from which tool company (s).
Mentors can be found and many have a real desire to help you build. If the local EAA groups is available to you, then I suggest that you join up. EAA groups vary from social groups to groups in which there are active of past builders. Find a group that has active builders and ask for help. I'll bet that one or more builders will be glad to help you.
My mentor had previously built an RV-8. I understand that the RV-8 plans are crude compared to the RV-12 plans. The 8 is also a much tougher and longer build. We had to learn to follow the RV-12 plans exactly and in sequence - not jump ahead, etc.
I am sure that those with much more experience than I will add their helping words here on the VAF - this is a great group. Standby for their input. By the way, I will be available to you by PM here or on the phone if you wish. Best of skill to you!