If you enjoy development, start with web and learn other technology. I've been writing code for a very long time and have been a founder more than once. The key I have learned myself and from others is if you keep learning all the time, you can always find a home someplace.
Also remember, web development in enterprises is slower to change than in startups, so even say startups see web dev decline in 10-15 years in favor of some new tech or mobile only etc. Enterprises will still have positions and needs beyond that as they trail the startups considerably in changes, for valid reasons.