I'm going to agree with mastering the lens you have first. And by master, what I mean, is put it to the test, learn how to adjust it, how to take good pictures with it, learn it's shortcomings and it's strengths.
I got a camera with 1 lens to start. I learned how to adjust the settings, playing with one at a time to really understand what change I was making. I tried it in different settings, bright sunshine, low light, etc. As I went along, I first realized I needed a decent flash and some filters for specific situations. I bought a speedlight, a ND filter and a circular polarizing filter. I knew I was ready for a new lens when I figured out what I was struggling with with the lens I had.
I took me about 6 months of playing with it daily, then learning the flash, to figure out where my gaps were. For me, it was low light indoor situations with my kids. So I went with a 50mm next. My next lens ended up being an 85 mm just because I loved the 50mm so much and I was blessed to have a MIL who was gifting me the 70-200 telephoto lens. Your needs will probably be different than mine. But working with what you have first, will help you know what you're missing. Once you know what is frustrating you about the lens you have, it's shortcomings, then you come back here and ask a different question about what lens will fill the gap you've discovered you have.
Just my 2 cents as a fellow newbie. It can be easy to get overwhelmed with new lens and not know when or how to use all your lens well. I'm up to 5 lens now and while there are a couple I'd like to have for fun, I can do everything I do now with these lenses. Every time I get a new lens, I use it exclusively for a while until I learn it- the settings, the focus, the shortcomings, the awesomeness it produces - varies with each lens. I am getting so much better at knowing what lens to put in my day bag. Often I only carry 1 because I know what I'm going to be doing. For a weekend trip I'll sometimes take 2.
As you get out and use your equipment, you'll figure out what works. I just got a new camera bag based on what was and wasn't working for me in the field. Those are the types of things that just come with practice.
Congrats on your new camera.