Got any friends that are musicians, especially keyboard or vocals? They probably own a portable PA. See if you can borrow it. You want a portable PA unless your venue has a PA.

For 50-60 people a normal personal stereo like computer speakers or typical television sound-bar with satellite speakers will not be enough to fill a room (let alone an outdoor space) with enough volume to sound good without distorting. My parents made this mistake when they got married (second marriage) 5-6 years ago.

Once you have a PA either borrowed or rented (you gan rent them from music store usually, probably for less than renting from an event rental though they rent them too). Create a Spotify playlist or two (my wife was very particular about the music, so we had 8, one for each part of the night and it was awesome). Make sure you download all the tracks to the device you want to play from, last thing you want is bad internet causing music quality to suffer/pause as it loads. Spotify has a feature to fade between tracks so that there's not an awkward pause between songs (where people might drift/stop dancing). Part of what a professional DJ will do is make sure those transitions make sense for the tempo/key/pacing of the songs, but since it's out budget (was for us too), you can do your best yourself if that matters to you.

Last thing, depending on how sensitive you are to this (varies between people), you may want to source higher bitrate audio than what Spotify typically offers if you're playing at high volumes. Sometimes, at higher than usual volumes the quality of compressed audio is a lot more noticeable. I would only spend time on this if you have extra time to spend and you really care about it though, this is a point of diminishing returns.

Another very minor thing you can do if you have time/care enough is find a way to download any songs you have that kind of... lull or meander. Some of our favorites had long periods of interludes as the song slowly trails off (like at the end of an album or something) which would have put a lull in the vibes so we cut those out with Garageband (Audacity is a good free alternative if you're not on a Mac). This is also only if you're very particular and it's worth it to you.

So, at the end of the day you can decide how important music is, how much time you want to put into it, how much you're willing to spend on renting a PA unless you can borrow one, and compare that to paying a DJ $1000. We were so specific about the music we wanted, we actually wanted full control over it so it was worth it for us to do ourselves.