How much increment should I expect after 1yr in startup?

I wouldn't hold out for a payrise! The best way to move up when you're starting out is, unfortunately, to jump ship to a different company. It's always good to be browsing and taking interviews even if you're happy at your current place. Some companies do very basic webdev, some do more complex, some do things very badly and don't care about how their devs progress. Sometimes moving to a new place exposes you to new concepts you didn't know about. How much the payrise will be depends on your skills, as well as the responsibility you're able to take on. It's definitely NOT to do with how long you've been doing the job, although of course your skills will improve over time.

Don't stress about it too much, just focus on improving your skills and becoming a more flexible and responsible developer. If you're working with something like React and you're good at it, you can expect a payrise in comparison to your first couple of jobs. But be aware that the more you learn, the more you realise you don't know. There's a lot to learn you may not be aware of yet. Keep taking on as many different (especially larger) projects and consuming information about programming in general. The rest will come with time and patience.