You cannot directly make a free website of your own. Website domains are sold by big companies which control the web like Google. They don't allow you to make free websites as that is their main source of income. They sell the domains of website. Depending on the type of website you want, different domains have different costs. Domains with popular keywords are expensive. Other factors on which the cost depends include the type and amount of content the website can handle, the number of images it can handle, etc. Domains can be bought at a rate as low as RS 99 per month.
The indirect way of owning a free website is that the web address or the site address will have the name of the website provider in front. There are a number of platforms which allow you to own such websites for free, although you don't really own them. They can make changes to your website or remove it whenever they want.
Now coming to the point of earning money from posting product reviews online, if you are a beginner, earning money should not be your focus but posting such reviews that people particularly search for your reviews should be your priority. You would have to be dedicated to your website, post reviews regularly, reply to your audiences quickly and politely, do a lot of hardwork, make your product views very popular and the most important, invest as much time as you can in it. When your website becomes so famous that it attracts a good number of customers, you will be able to earn a good amount of money. Here, by 'good', I mean real good money. You will have to wait for atleast a year to start earning good amounts if your website starts attracting people.
Overall, its a bit tough work but hardwork and real dedication and a bit of luck can help you to achieve it. Since you are a beginner, I would suggest you own a free website through a third party rather than spending money on buying a website or domain. As you get deeper and deeper into this, you will yourself learn more about it.