The free account is very limited, you are so right about that. There are a few ways for you to earn an upgrade without needing actual money.

Once you send 50 reviews, you will have some gift points that the system gives your for reviewing. There are also items set up with an auto reward that gives you even more gift points. You can find those here: https://www.writing.com/main/list_items/type/autoreward

Also once you sent those 50 reviews, you can petition "RAOK Upgrade Brigade Group"  for a three months upgraded membership. The upgraded membership is the sweet spot of memberships. I have that. It gives you a good amount of items and item types. It's also not very expensive in comparison to the higher levels. You really only need a premium account if you want to do a lot of things like have large groups or upload hundreds of photos.

There are also other groups and even individual members who will give you a paid membership if you show yourself very active and involved on the site.