It is very simple. You just go to the top left in the workshop and there should be a slide down option. If you are building you are in the 3d modeling part. So if you click that it will bring down an option to move to the rendering part. There are a lot of settings that you can change to make your set look more realistic, but originally you should try to stick with the defaults. I hope this helps.

If this Helps, I've actually made 3 Tutorials on my YouTube Channel, so, here's the Playlist:
https://www.youtube.com/playlist?list😛L0SxPuM1VndHf9V5B9d3Uz1C7LS_2B_Jw
I hope it can help! 😄

Hi, I am new to rendering, too, and I probably have some simple questions:

1. What are samples? Couldn't figure that out, yet.

2. Under https://www.mecabricks.com/en/credits it says that I can render an image with up to 20 MB for free. However, whenever I export a jpg or png, the size of the jpg is just about 50 KB (png 300 KB, 1263 x 545 pixel). My model is not very complex but I need an image in a higher resolution to be able to print it.

Thanx and Regards
Oliver

Resolution for free render is 0.7 Million max. If you want higher resolution you need to buy credits and use them. Your resolution 1263 x 545 is 0,688 million pixels so just under the limit.
The reason for this is that the hardware Scrubs have bought for the render server is not cheap. However, it's fast and you can make very many renders for the same money you would have to spend on a decent computer to get the same render times...

Thanks @Sealund!

I totally understand, why we should contribute financially. I'll buy some credits and check it out.

Any tip regarding the correct amount of "samples"?

I'm not a render expert but i think lower samples means more "course" render. The higher the better but there's a limit when its not noticeable anymore. I think around 200 which is the limit for free renders is sufficient in most cases. The more samples, the longer render time which affects the amount of credits used.