How do I refactor my SVN project to properly branch and merge branches?

Question

subversion

There is a repository: /var/svn/reponame
As well as a web project: /var/www/site.ru
I'm running Windows, using TurtoiseSVN as a client. Since I am working with SVN for the first time, I did not create any branches, trunk, tags (as far as I understand, not necessarily), everything is in one directory.
Question:
How to branch correctly so that you can maintain several different branches of the project in parallel, and then merge with the leader as tasks are completed?
How do I:

1. I branch TurtoiseSVN->Branch, I enter some other path, for example, I add /fishka1
   
2. Switch to this branch TurtoiseSVN->Switch
   
3. I work in this branch, I make a couple of commits
   
4. What's next?
   

Switch back to master, do TutroiseSVN->Merge... Select merge with revision range. From - I specify the main branch, merging with the revision - I specify the latest revision of the branch. Everything passes and in the end nothing. All changes are lost. Please tell me the correct sequence of steps

Answer 1

Install GIT and enjoy branching.