I would recommend the retriever trainer (
www.theretrievertrainer.com). It is only $60/year and a very good program. you also get access to the facebook group with pro trainers as well as other DIYers who may be experiencing the same issues as you. Training the dog yourself is a great bonding experience in my opinion. I would give it a go on your own first and you can always employ the help of a trainer for specific issues you may be having trouble with.
When you get the pup, dont be so eager to jump straight into formal training. You do need to start "training" for confidence and prey drive from the moment you bring him home. Take him for rides in the car, boat, ATV, etc. Let him chase that squirrel. walk out in that knee deep water and show him there is nothing to be afraid of. Take them on hikes and let them explore, sniff things, etc. If you have a buddy with a hunting dog, or even just a dog that loves to swim and fetch and get a little rowdy, let them hang out and that confidence will translate over much faster.
Goldens can easily be shaped into a timid house dog, but they can also be shaped into an awesome hunting dog with no fear and plenty of drive. That part is on you and starts from the moment you bring them home. I've got two goldens i trained up myself, and they're certainly not perfect by any means, but they're my best buds and i wouldnt do a single thing different. As an added bonus, ive lost 40 lbs in the past 2 years just from running them around. Sorry for the unsolicited rant, but when Goldens and hunting come up in the same sentence i just cant help myself.
https://i.imgur.com/ho1jXDo.jpgApparently idk how to post pics
https://instagr.am/p/CN7vXuWjb6v