Well, let me share some details about my experience then.
When I have started learning about HTML and CSS, I made a free website with webs.com. Initially, it's working fine and after like 6 months or so, I was facing 'This website is down. Kindly contact our help desk' message a lot. I got confused and raised a support ticket with webs team. I was told that my website got too much traffic and they had to take it down for the sake of other websites, which are using the same shared hosting. Then, I was asked to upgrade my account.
As I have never used a credit card before, I switched to co.nf provider. Initially it's fine and later I got 503 error. When I contacted the support, they told me I will have to upgrade to a basic account.
I switched to 000webhost and this time, I used a forum software(myBB). After a while, the same thing happened. I told them, I need at least the database files to move my forum elsewhere and they told me to upgrade the account to get that information.
Finally, I switched to GoDaddy hosting and it's a paid hosting account. Even now sometimes I get the 503 error but most of the time it works fine. After all this, I have stopped believing in free stuff.