So I recently had a stroke of genius and finally got a business idea that is worth sticking with.
Briefly: I have gathered a team of people to offer online services to clients (locally in my country). These online services would have to be purchased online and I would get a small commission from each purchase. The product is one, so I need a website that must have some sort of database system to store clients, the users in the team, completed orders, active orders (tickets) and some other minor stuff. It would also have to have a "back-end" board for the working team to see active orders and access their details. Ideally I have to also embed the html PayPal add-in to accept card payments. I have little experience in web development, but this is not a too complex project with a relatively simple and small structure, because the business itself will be quite small. The choices I am looking into are Wix, SquareSpace and WordPress (which I would have to learn through a course). So I would immensely appreciate any feedback from people who have experience in this field with such websites. Is it worth undergoing the hassle of learning then implementing the whole WordPress system, or could I make it work with just Wix or SquareSpace in your opinion? 
An immense thank you in advance to whoever took the time to read this and whoever will help out.

Why not just use the team of people you have gathered.

however, avoid wix and square space. You don’t need to do a course to learn Wordpress.

What you are offering will need a lot of development. It’s not complicated but it’s not a quick fix. What’s your budget for this project? 

49 minutes ago, fisicx said:

Why not just use the team of people you have gathered.

however, avoid wix and square space. You don’t need to do a course to learn Wordpress.

What you are offering will need a lot of development. It’s not complicated but it’s not a quick fix. What’s your budget for this project? 

So regarding the team of people, I'm not using them because they're my college pals, they have about the same level of knowledge as me and they're not too serious about business and such. Making them do a single task from time to time in exchange for money works well, but they would not take the time to learn a side skill and put in work for a business project. Regarding budget, being a college student, I am planning on learning anything needed off of Udemy, which my employer provides, and Google. I have some money but apart from hosting costs and perhaps some marketing (which is also not much needed, I have a decent network of people to spread the word, target clients will be small businesses), I don't plan in investing into someone setting this up for me. I am not in a hurry, I've set a deadline to myself of about 2 months for this project to learn and implement everything.
Anyways thanks for the tip, will look into Wordpress, but regardless of that, may I ask you why SquareSpace and Wix should be avoided?

It's going to take you a lot longer than 2 months to learn how to do everything you want.

There are ticketing systems you can use but none of the good ones are free. Zendesk for example is about $50/month.

And you have vastly underestimated to cost of marketing. There a dozens of freelancer platforms all spending big money on marketing. You have little chance of getting noticed outside of your very local area (geographically and socially).

Wix and squarespace or any other online site buider won't let you install the necessary apps or code.

25 minutes ago, fisicx said:

It's going to take you a lot longer than 2 months to learn how to do everything you want.

There are ticketing systems you can use but none of the good ones are free. Zendesk for example is about $50/month.

And you have vastly underestimated to cost of marketing. There a dozens of freelancer platforms all spending big money on marketing. You have little chance of getting noticed outside of your very local area (geographically and socially).

Wix and squarespace or any other online site buider won't let you install the necessary apps or code.

I have some basics behind my back, I know some html and js and have created simple websites in the past with different services. I'm willing to put in a lot of work into this and I'm not planning to go onto international scale or compete with any freelance websites. I have a very specific service with a specific price tag on it aimed specifically at small local businesses, at most it will be businesses in my country (since aimed at non-english speaking people with little knowledge of market and computers). That's why I'm not disclosing the idea, I wholeheartedly believe this will be something that will attract attention in a market with little to no competition, especially with the price tag put on it. At worst this project will give me enough experience to practice website creation as a side-hustle, so win-win.
Thanks again for the input, appreciate it!

I would recommend using Squarespace here as it's rather modern CMS. 

3 hours ago, Ann87 said:

I would recommend using Squarespace here as it's rather modern CMS. 

Except it can't do what they want.