Is it safe to plug in computer anwhere in my house?

The purpose of the surge protector is to protect your computer & it's power-delicate components from becoming a nice golden brown crispy color (which is good for some foods... Not so much for PC parts) should a power surge OR lightning hits your house. In that case, the surge protector would get fried instead of your PC components that would cost hundreds to thousands of dollars to replace.

Ideally a UPS (Uninterruptable Power Supply) is ideal to it serves both as a surge protector (preventing your electronics from getting damaged from power spikes) AND emergency back-up battery (preventing your electronics from suffering sudden power loss OR power dips) for provide maximum power protection.

If you don't mind the potential risk of electrical damage to your PC... you COULD just plug it into any outlet, but most home computers usually require a minimum of 2-3 outlets (One for the system, One for the monitor, One for the speakers, if not built into the monitor). If you have an All-in-One system, you'll be able to get by with one outlet... HOWEVER, any accessories you have like a printer would need an outlet as well... which is why surge protectors are recommended since they have multiple outlets you'll need.

It depends on the quality of the wiring and stability of the electricity supply where you are. As a rule, any socket outlet should be fine. In reality, some of us experience power spikes so a surge protector is always a sensible precaution. Some years ago, my router and PC were damaged when lightning struck the telegraph pole where my service connects. I now use surge protectors on everything sensitive. As far as I know, it has never been needed but it is a lot cheaper than a new PC and router so I'll keep using it.