Hi I think both of them are important for your online business. SEO bring natural traffic and Social Media brings a lot of young people. Also social media can be good for branding too. I hope this helps.
I agree with you, You can apply both strategies to start your business and if you want to increase the traffic of your website, you should need to work on Google SEO.
Both. SEO is for the long game, and it'll get you a far better ROI. Content marketing + webinars give the highest possible ROI of any traction channel. SMM is a good way to see results quickly, and how much you invest really just depends on your budget. Start there. Figure out your budget + target/tribe, and go from there.
SEO will take a lot and lot of time. But this doesn't mean, you should not choose SEO for your business. With time, you will start getting results. SMM, is something, if you have social profiles where you have good number of active users, then go ahead and post on social media. Your friends/family/enemies can help you get you orders quickly.
Your best bet would be to use it at the same time, as there isn't any reason why you would choose just one of those tactics. SEO is usually free and it doesn't necessarily require some investing, especially in the beginning, and here you need to concentrate more on optimizing the site, compressing images, researching the best keywords, writing quality content, implementing good links, and so on... At the same time, while you are doing this, you can also try to make some paid campaigns on social media or Google Ads and target important phrases there, as this will get you much faster results and increase the site's traffic. If you combine SEO and SMM, you will achieve the best long term results.
got some budget? Obviously buy the traffic. Have no budget? Then SEO and other content marketing is the way to go. or even, tell your riders/ drivers (whoever deliver your food) to promote you.