It took a couple months in the game before I equipped any items. I think basic clothing are assumed, though others may disagree with me in that- in that case, Kraak flew a ship around nude for a month of two before he put on a set of armor and a cloak and backpack.
An example of how many experienced players equip. I wish I had some of this stuff.
How to buy it, how to get it assigned (mostly ships, or unowned property), how to put it on, and how to use it- all challenges for the new player (not to mention getting the credits it costs). I'm not yet any sort of expert. If you own an item, you can click on items on the members menu, and then the item ID# will tell you the items' location and what ship/planet it's on and who, if anyone is carrying it.
How to buy items? Start with people you know, or within your faction. Later, you'll want to learn to use Centrepoint Market, which is a lesson all in its own that can take a long time to master. Compare prices and feedback before you buy something there, and be sure to note the location- are you going to make a 2-week round trip for some bacta patches, or would you rather pay another 50k for one that's 5 days closer?
I'm half trying to help new players, and half trying to equip my own PC, which is an endless process. Any questions you have will probably be answered by someone with much more experience than me.