After clicking with a simple point and shoot I develop my in interest in photography and purchased my first DSLR in January 2015, it was an entry level Canon 700D / T5i bundled with the kit of 18-135mm. Along with this I picked up the 50mm F 1.8 (non STM version) which is the best cheapest prime you can get for less than $100 USD.
I found that the kit lens (18-135mm F3.5 – 5.6) has been used the most in many shooting scenarios. Only if I decide to give it a break for a day or two I put on my nifty fifty (50mm 1.8)
On a APS-C 18mm equivalent to 28.8mm (with 1.6 times crop factor for Canon) is a fair focal length to do streets.
When I have to do street portraits, I zoom in and move close to the subject. Because this is not a prime lens the aperture changes to 5.6 which is still reasonable for a portrait and creates a slight out of focus background.
It is always good to push the limits of your kit lens and make the best use of what you have. This will be a sort of constraint however, this will let you get creative and the put the lens to its best use.