Ok number one, happy, well rounded and obedient is a Labrador’s natural state!
Toilet training: take them outside every half hour and after food. Take time out before their breakfast. Go out with them at first and praise them and you can also teach a command, I say “go do your wee wees”, so you can get them to go for example before bed or before you go out. Both of mine have been toilet trained in the first few days and each had one poo accident in the house ever.
Basic commands: food is your friend! Labradors will do anything for food and they are smart. Both of mine learned sit on the first day for example. Also use a different hand signal for each command as it helps them to learn it. Good commands to learn are sit, down, wait, leave. Always be consistent with the word and signal you use.
Leash walking/ recall: my first lab never learned to walk nicely on the lead, my second walks perfectly and I’ve no idea what we did differently! Recall is easy, they’re bread to come back to you. Let them off straight away and teach a recall command (we say “here”). Wait is also useful so they stay put once they’ve come back to you. Teach them to only go up to other off lead dogs when you tell them they can.
Chewing: you just have to deal with it for the first few months til their adult teeth come in. Labradors are very chewy. Natural chews like pigs ears, bully sticks etc are really helpful and my labs must have a teddy in their mouths at all times 😂.
Jumping up: this is a hard one as they lose their shit with excitement when you come home. We fold our arms and say sit and won’t greet him til he’s sitting. Don’t fall into the trap of fussing that tiny puppy when they jump up to greet you as they get very big, very quickly and even then they’re little, those claws are sharp.
My best advice is ignore those trainers that say you can’t teach a dog “no” or “stop”. You can, if they can understand “dinner” and “cheese” they can understand “stop”! My puppy will never instantly freeze if we say “stop”. Oh and never forget the praising part, that’s the bit that tends to get forgotten. So, “stop” then praise and strokes, then another command if you want them to do something else, if that makes sense?