2years 4 months between my two.
First few weeks when we were all at home together my oldest one was just in awe of her baby sister. We then struggled a bit months 1-6/7 as all my eldest wanted was her daddy - for EVERYTHING so I think that was due to me always having the baby.
I made a massive effort with things like a special game / play thing when I was feeding baby that I could do with the eldest. When baby got better with napping on her own then I used to do things with the elder one - even if it was watching a movie so I could relax.
Use the tv to your advantage - we don't have it on a lot here but I put it on when I want older one to be distracted so I can do something with the baby.
Lots of other tips like buying your son a present "from the baby", there's better and worse ways to introduce baby to your DS - have a read back through other threads.
Buying a book might help - we had one along the lines of "there's a house in mummy's tummy" or something like that.
Now the little one is 10 months and for the last couple of months they have been thick as thieves, ADORE each other, always looking for the other one / sharing toys & snacks etc and generally play really nicely together. Maybe 10 minutes of every day when we get push back from the older one and that's usually when she's just woken up!
It was hard at first but so worth it now.
Your relationship and time with your son will obviously change - something I hadn't thought about too much, so enjoy doing things 1:1 with him now and when baby is a bit older factor in some time to dedicate to him.
You've got this x