Hi,
I work on the principle that I'm as good as my imagination; if I can think a job through then I can do it whatever the job is.
Hang around and watch your builder at work; it's amazing what can be learnt whilst watching over someone's shoulder. Don't disappoint yourself by tackling a big job first then failing it will put you off for life; start with small jobs and build on small successes; no one was born with skills so we all start from the same base and even the best still make silly mistakes.
When I started DIY there were no home computers; no email and definitely no "how to" videos in fact tradespeople were very secretive about their skills. I'm also a huge fan of YouTube but care needs to be taken because there are videos and working methods which make my toes curl due to dangerous practices shown; common sense is one of the very best learning tools; if it feels wrong then don't do it.
There are also lots of forums some quite specialized such as vintage radio forums I'm a member of; never feel intimidated by any of the forums; I didn't know a thing about vintage radio when I adopted it as a winter hobby and joined my very first forum; ten years later I had articles published and was honoured with a top award. Never let anyone put you down or put you off; the best motive I receive is when someone tells me it can't be done?
Visiting DIY stores and seeking advice can be awkward at first due to not knowing what things are called but generally if you tell someone you are a novice they will fall over themselves to help; if buying materials buy extra to allow for mistakes it saves a lot of running around. If you have space collect all manner of things that will come in handy someday; if you visit a timber yard be nosy and politely ask if they have any offcuts; they usually ask what you are looking for; just say anything at all because I'm a novice and would like to have offcuts to practice with; always say you are willing to pay and never mess anyone around.
I've visited local joiners shops and sheet metal works asking for offcuts; I'm never a pest and am always most polite not wanting to be a time waster. A very good example is a recent project I tackled;
https://www.diy-forums.com/threads/metal-spinning.289525/
I needed six aluminium reflectors so I made six. I have more determination than skills; anyone can learn a new skill if they try hard enough. At work a guy was employed as floor sweeper and he was forever the butt of jokes; I got him transferred to my departments and taught him how to use a computer and industrial printer to print consignment notes; I also made use of him having him painting my offices and at weekend he would work Saturday afternoon and all day Sunday with another team member on jobs that couldn't be carried out whilst the factory was in full production; this guy in the end was better off than lots of skilled workers who only worked the basic week. Anyone who states they can't do it are correct but it doesn't mean you can't do it?
I don't want to preach because it seems the more I learn the less I know and I'm not an expert in anything in fact I never want to be an expert; making mistakes isn't the end of the world in fact it's where most is learned; just don't hurt yourself or anyone else. Buy the best tools and materials you can afford allowing you to do the job to the very best of your ability; do the job and do it once only; never bodge a job it will only come back to bite you.
Once you start succeeding with small jobs you'll earn a new respect from others but most of all you'll suddenly feel a real sense of satisfaction; it's all yours for the taking.
Just me rambling on as usual.
Kind regards, Colin.