In this forum we basically have service advertising sections.
These are sections you will find people advertising for services they offer or look for people/services to hire for projects and payment is usually through bitcoin or altcoin.
Since you are a beginner, you can first start by joining projects that are looking for people hire and then as your portfolio grows you can start advertising your services in the sections(people always trust someone who has been quite reputable and has a good past work portfolio to show)

You can check out
- https://bitcointalk.org/index.php?board=84.0 - For bitcoin paying related services
- https://bitcointalk.org/index.php?board=197.0 - For Altcoin paying services.

I would also recommend you use escrow services for you deals or transactions to avoid getting scammed.

There are also a couple of websites I know that require you to do some tasks such as designing code, graphics, writing blogs or find bugs in exchanges for Ether or other altcoins.
The tasks are advertised daily by different projects. Most of the projects are already established and chances of wasting your time are really very low so long as you present quality work since everything is handled by the smart contract

They Include
- https://gitcoin.co/ (Very good for a github lover)
- https://bounties.network/
I have used them recently and they seem awesome. You can try to look into them.
Good luck with your pursuit