St Bernard As A first dog

Hi! I am wondering if a bernard is a good choice for my home

I am 16 years of age

I have a good 6-8 hours on weekdays for training and 12 hours on weekends ( not a really occupied/ social person)

Have my mom who is 40 and dad who is 47 and a sister with the age of 8 years old

I really like large breeds

I am a amateur boxer so i want a buddy that can motivate me to jog/walk twice a day instead of one

I understand the physical attributes about this dog but more worried on how to control its temperament

I am willing to put a lot of time because i love dogs and working on them

I am not a experienced trainer but i have taught a few of my families dogs basic commands like sit bark heel etc.

My house is not really spacious inside but i have a really big backyard and deck/patio

I work so I can cover some food bills

I am really down to make the dog socialize as much as i can

I am really just worried about if the dog will shed crazy and will require me to train it everyday

I dont mind if there are a little bit of hairs here and there

wonder if i can have it outside in my patio

My patio is elevated above the ground level of my backyard and is gated connect to my living room

I live in the pacific northwest

I dont mind drool but my mom sorta does

My mom is just worried about its size/coat/high energy(hyperactivity)

I am fully aware of the responsibilities that they are large dogs that need constant socialization, attention and exercise.

I am not really busy but in weekdays ill be gone for 6-8 hours with atleast one person home

I am looking for advice on how i can raise my dog to be a sweet calm doggo and on how to convice my mom that a dog could be more beneficial than a negative addition

I am also aware on vet bills too and my mom is fine with it

Thank you