Newbie here! :)

Hello everyone just to introduce my self my names Laura, I'm 21, I'm engaged And together we have a 8 month old boy and finally got my finances other son who is turning 1 this Friday!
I'm a busy mumma as you can tell, how do any of you mums find the time to exercise?
This is my routine that I have,
Monday's:
Play day from 9:30 am till 11 am
Then from 6pm till 9pm I have college
Tuesday is my chill out day and usually do the shopping
Wednesday I go round my sister in laws for Half the day
Thursday I have another play day session from 1pm till 3pm
Friday messy play from 10 am till 11am
Saturday rest day
Sunday usually go for a drive with my dad and son

I know it really doesn't seem busy at all but because he likes to have all the attention on him I find it hard to get my own time, whilst he's sleeping I'm doing my maths homework and catching up on missed out sleep, the only time I get time is when I'm in bed.
I was thinking yoga but because me and my son share a room he'll wake up as I'm quite clumsy and if I leave the room he'll wake up.
I would walk somewhere local but I live around hills making it hard because of my bad hips, soon my dad will be starting work so I wouldn't be able to get dropped off anywhere where I am able to walk, my partner doesn't drive he relies on buses but I have no buses near by me with having to walk up 3 hills