Update README for first us of backend and add Troubleshoot section

[alberttkt]

-Added a new command to set the backend for the first time and
-Solution for a possible error during the setup

[CLAassistant]

All committers have signed the CLA.

[coveralls]

Pull Request Test Coverage Report for Build 3143662239

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 58.5%

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Totals
Change from base Build 3103604593:	0.0%
Covered Lines:	2364
Relevant Lines:	4041

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💛 - Coveralls

[nkcr]

Very minor comments, fine otherwise :)

[sonarqubecloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

No Coverage information
0.0% Duplication

[coveralls]

Pull Request Test Coverage Report for Build 3143662239

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
• To avoid this issue with future PRs, see these Recommended CI Configurations.
• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 58.5%

---

Totals
Change from base Build 3103604593:	0.0%
Covered Lines:	2364
Relevant Lines:	4041

---

💛 - Coveralls