male rat introducing it to another male rat?

[Lizzy]

i got a male rat about a week ago and next week im going to buy another from the same pet shop so my rats most likely will be brothers but might not but they will be close to each others age my rat is about 2 months old or younger

so my questions are:

if there brothers will this make it easier to introduce?
if both are still young should they get along?
do most male rats get along with each other if introduced at a young age?
will this make it easier to socialize them?
if they get along straight away could i keep them together straight up?
Should i still quarantine the new one?

i have researched how to introduce them but any advice would be very much appreciated.

Thanks