You’ll notice all kinds of variations on the set up. If you look up the class rules you can see the limitations. Just pick one that makes sense to you and then tweak it as you go. Here’s a simple set up from Collie sails.
Fill the mast step with water and see if it goes down. Also do an air test with soapy water. Cover hull and deck with soapy water and pump air into the hull through the bung hole. Use a hand pump only. Take the bailer out to check the brass fitting during the air test.
.....also the laser class has a junior membership that gets you a quarterly magazine. The international class site also has links to tips and advice. The dealer websites usually have good simple videos about how to rig the boat. So check out Rooster and west coast sailing and colliesails.
My 14 year old made the switch from Opti to laser 4.7 over the winter and has loved it! There are good instructional resources online. Plenty
Also look at RYA YouTube channel.
This i a link to a 3M resources page. If you look under the heading “gelcoat finishing “ you should find info on removing the oxidation and polishing the gelcoat. Wash the deck with a stiff brush and soap. There are fiberglass stain removers your can use also...