Your connections look as if your solder does not have flux.
Are you using Lead Solder that includes flux in the center?
For general electronics such as circuit boards, i would recommend Ersin Multicore 63/37.
Also readily available is Kester 60/40. The first number represents the % of tin.
the second is the % of lead.
Solders to avoid are 'plumbing solder', 40/60, 50/50, acid core and solder with no flux in the core.
Avoid "lead free" solders until you have significant experience soldering.
As a hobbiest, the amount of lead you would expose to the environment is trivial - IMHO.
The rosin flux greatly helps the solder behave. The flux helps the solder flow easily.
Adding a little solder with flux will often 'clean up' a joint that was all pointy.
You can also purchase just the flux. If you buy flux, get "activated" rosin flux.
This rosin flux is often available in the plumbing section of hardware stores.
Look for it in a small round metal can similar to what 'smokeless tobacco' comes in.
A tiny amount on the tip of a toothpick or match-stick will probably be more than enough
to make a single solder joint look all smooth and shiny as it should.
Good Luck, John