Setting up an infrastructure for your web presence is not difficult, but it will take some time and effort. There are, as I see it now, at least 4 components:
Set up a upi
A upi = unique personal identifier.
Set up your own url and web site
A url is the fundamental building block of the web. Along with a upi, I believe everyone should own a url that belongs to them.
Once you have a url, you can set up a web site using this address. You could use a free-hosting site but my recommendation is find a ISP that is manageable cost wise and pay for the site. This will give you more control over your site and it is less likely the provider will suddenly not provide a ISP service. To some people it may seem a little daunting to set up their own web site, but in fact it is not difficult - and for a small cost a web developer will do the job for you anyway. For a small fee a developer will also update your site for you as you add new material.
The main purpose of your web site is to start linking web material about you. Keeping a lot of your stuff (apart from written web pages such as this one) on the actual web site is not necessary and could be quite expensive (requires a lot of memory). - In the future this may not be an issue as even "cloud" storage space becomes more cost effective.
The main point is that once you have a upi, a url and a website you are in control and you are on the way to ensuring that you have a pervasive and enduring digital presence.
Build on some existing sites such as 1000memories, blog sites and so on
Once you have a web site operating begin to develop material on existing sites. When you have registered for a site such a 1000memories, or a blog site such as wordpress, link it to your own web site. You can now use the tools and applications within the web application to develop your material, but access it via your own web site.
Use the web across a number of platforms in your day to day activities
Keep using sites such as Facebook, twitter, and so on as per normal. Places to keep photos and video should be used in the same way.
For example, decide on a provider to store and manage your photos and consistently use their web site. Link it to your web site and ensure the storage area links to your upi as much as possible.
Become familiar with your infrastructure and use it!