I'd recommend - as others have - a Mesh system. Just be careful of what you buy, if going that route. Some can be exorbitantly expensive with all kinds of home automation features, etc. You're really interested in extending wifi coverage, so for now, there's no reason for overkill on that score.
(One quick aside - others here have recommended "Powerline" systems. I've used them and they work well
for me, but Powerline is a "your mileage may vary" proposition. Powerline ethernet works by connecting a base Powerline box into a wall outlet where your router is, and then connecting the base unit to your router. Then, you take another Powerline unit to another room and plug it into the wall, and connect its ethernet (or wifi, if it has wifi) to your far end device. What's "your mileage may vary"? Powerline systems require the base unit and remote unit(s) be on the same electrical grid or block in your home. If the rooms you're using are on separate electrical grids (probably not the right word), Powerline might work very slowly or not at all.)
If you get a Mesh system, you need to get one that has three units included. DON'T just buy a single "hub"- that's not going to help you at all. You need to get a three-unit system so you can place the hub where the internet connectivity comes into your house, and then put the other two units in other locations in the house (bedroom? lanai?).
Mesh is really a plug-and-play system, in essence. You normally use an included smartphone app to set these up. Plug in the hub, follow the instructions on the app (network name/password, etc.), then once that's done, move to the other areas and plug in those units. The phone app should detect these right away and configure them.
What's a "reasonable" Mesh system in terms of price? The TP-Link "Deco" Mesh system is $170 from Amazon now. (Note: There's also a "Deco PLUS" system that's more advanced - and more expensive - but I'd go with the baseline system right now just so you can try it out and see if MESH is going to work for you.) Some high-end Mesh systems can cost $300-$400 plus. So, to try Mesh to see if it's going to help you, I'd go with a highly-rated, reasonably-priced system.
TP-Link "Deco" Mesh System
If you want a primer on how Mesh works in your house, take a look at this video. You'll see it's really a case of connecting the base Mesh unit (aka "node" or "access point") where your internet service provider has brought internet into your home, configure it quickly with the smartphone app, then connect the other units in the "dead spot" areas of your home and let the smartphone app configure them, too.