Obviously, you must have an OS on it Then you follow up with making sure your drivers are to the latest. If you're unsure of which drivers to install, it's a good idea to pass on the SKU for your laptop in order for us to locate the support page and/or it's drivers.
If you're asking about app's, well, I don't use third party apps to manage my OS apart from CCleaner which is used to occasionally clean out registry and cached temp files. Outside of that you won't need an anti virus so long as your browsing behavior is towards safe sites and you don't click on fishy links.
Speaking of links, you can use Google's Chrome or Mozilla Firefox but Chrome would be more resource intensive on your 2GB off the laptop.
Edit, did you ask for suggestions about software installation or a hardware upgrade?