If you have a machine you can spare, please run a full node. The more nodes there are, the stronger the network is. Also, if you run a full node you can potentially mine your node for information of various kinds. You can tell if you have a full node by giving the following command:
bitcoin-cli getinfo
If the "connections" field is greater than 8, then you are running a full node, congratulations!
You can find information on how to run a full node on bitcoin.org here:
https://bitcoin.org/en/full-nodeBut PCs need to be pretty configurable and online continuously! Full node mode is very secure because it is certainly not fraudulent. But it is not convenient with small traders