You might find an option that suits you.
The fact that you are a single mother doesn’t really affect your application (as long as you have enough money to sustain yourself and your son for your first six months in Canada – you may find the exact amount in Canada.ca)
I’ll try to sum up the two most popular paths:
a) Express Entry via Federal Skilled Worker:
You create a profile and then you’ll be given a score based on:
1. Your age
2. Your English (or/and French) level
3. Your education
4. Your work experience
After that, you enter a pool of candidates. Almost every two weeks the government sends a round of invitations to the highest scores in the pool. If you are selected, you send all your documents and if everything is ok you receive your PR.
b) Studies
You enter Canada with a student visa to study a program of at least 1 year (ideally, at least 2) in a college or a university. Once you finish your program, you’ll have an open work permit for the same length of the course you took. During that period, you need to find a permanent job offer in the same field of the program you took. Once you have 1 year of experience, you can apply for a PR.
Keep in mind that:
- While you are studying, you’ll only be able to work part-time, so consider you’ll need enough money to sustain yourself and your son during that time, and the fee for international students is significantly more expensive than the fee for locals
- If you chose this path, you´ll apply through a provincial nomination from the province in which you studied; each province has its rules to give you the provincial nomination
- English courses don’t allow you to apply for a PR (nor every course offered by a college or university, you’ll need to verify if the course you are interested in has the option)
That’s pretty much the big picture of the two more popular paths (there are many other paths targeted at specific profiles that might as well suit your case). All the information is in the Immigration section at Canada.ca, that's the most trustworthy source of information.
Hope this helps