At a minimum, some tool bits, I recommend getting unground tool HSS ones and learning to grind your own but preground carbide are OK, I just don't think that much for carbide ones for general use on softer materials.
I'd also recommend a MT3 live center for the tailstock and a MT3 shanked 1/2 inch drill chuck for the same. Drilling is a rather essential operation on the lathe right from the start.
Get some aluminum round rod (6061 is common and a decent machining grade of aluminum) and maybe some brass rod as well to learn turning operations ranging from facing and turning to threading and drilling. Easier -IMO- to learn on softer metals than harder ones and you will probably use more brass and aluminum than steel for the most part anyway. Get stuff ranging from about a quarter to an iinch and a half, scrap yards are the cheapest place to find them if you have any metal scrap yards in your vicinity, new bar stock is at the top end of the pricing for the material you want if you can find appropriate sized scrap you save a bunch on stuff you'll probably toss out during the learning process.
You probably already have stuff like drill bits and center drills, but if not consider getting them as well since you will be needing them in short order.
That should keep you going for a while and anything else you end up needing will become apparent as your skills develop. Buying a bunch of stuff ahead of learning to use it will likely end up with a lot of tooling that just sits on a shelf because you ended up not really needing it.
BTW, I kinda like that lathe, been considering getting one myself for a couple years if I ever make room for it somewhere in my already overcrowded shed/shop.
