I agree with the other poster that you should continue working on your store, for example the main banner on the front page isn’t sized right for mobile. But for the most part you’re off to a great start! It looks like you have a good vision of the brand you’re going for.

My favorite cheap advertising method is to take a cheap product, I mean like $1-3 dollars from the manufacturer, and do a regular giveaway for it on your account with the way to enter being follow your account and like the post that announced it. This is really only effective if you can get a large page (that shares the same audience as you) to promote it on their page for you. I’ve gotten a few to do this for free by framing it in the light of “I want to let you do a giveaway for one of my products, free of charge. We want to build up brand awareness in your audience”. Make it sound like it’s a win for them, influencers are all about gaining followers and this helps them do that too.

In my experience that is the cheapest/fastest way to build up REAL followers and get some early organic traffic.

I am not very experienced, as a matter of fact we have not even made one sell yet, and our store has been open for a little over 2 weeks with over 100 visits, but we've been trying to optimize a lot to get conversions. How ever, for marketing it seems fairly simple if you have the funds from what I've seen. Mostly you want to figure out who your audience is by using a legit influencer to promote your product. Test it out, see what works for you to get your store sales, and then use the analytics from that to see who in your audience is most likely to engage and purchase your products. Once you find some thing that works, you scale from there. We have spent 5 $ a day on Facebook for advertising before also, and have got up to 60 or so visits to our site just from that, so that may help to test some things out as well. I do think there is more to it than marketing though, because like I stated above we've been open for a little over 2 weeks with over 100 visits and have not had one purchase yet, and we haven't quite figured out why. Make sure your site is presentable, and looks as professional as possible, and if you can afford it, purchase some of your own items and give them away to people who will appreciate it. Try to get a review and maybe some pictures of them wearing your product, I imagine the more of that you have the better your site will look also. Hope this helped some!

-Google is our friend

Youre thinking about this the wrong way. The fundamental thing to know when going about E-com is that you need:

Traffic and an offer. Traffic + Offer =$$$

Before you think about the product you are selling, you need to find a hungry market/niche and be specific.

You mentioned health,fitness, yoga. Think more specific like IE:

middle-aged, stay at home moms are into yoga. (off-the head example)

Learn everything there is about this group. (How they talk, what they need, want, hate,desire,etc)

From there, find a product that fits their needs. I recommend dropshipping off aliexpress through oberlo.

Another Tip: Before starting and possibly wasting some money, i recommend learning AT LEAST the fundamentals of copywriting and identifying markets.