If you see one of the more dangerous spiders, keep some distance. However, most spiders are not aggressive and will not attack unless provoked. You are much larger and more dangerous to them.
One thing to remember about spider venom is that the venom of a black widow, brown recluse, etc. is not more potent than the venom of other spiders. It’s just that these are the only spiders whose venom specifically seems to affect human beings. There are many spiders with more potent venom that doesn’t affect humans.