Besides need or desire to upscale your portable Mac to new/later version..
..There still is 'upgrade capability' with your 2013 MacBook 13-inch model.
The Apple store or online official Apple store could help determine the
value of your older Mac; be that some credit, gift card, or a trade value.
"*Trade-in value may be applied toward qualifying new device purchase, or added
to an Apple Gift Card. Actual value awarded is based on receipt of a qualifying
device matching the description provided when estimate was made."
Your mac's OS could be upgraded to Catalina; or maybe Big Sur..
download of a new/newer Mac system. To read/get downloadable
system upgrades, (recent versions are represented) go here:
• How to get old versions of macOS - Apple Support
https://support.apple.com/en-us/HT211683
Two of my late 2012 Macs have Mojave. That's an adequate 'bridge
system' for those of us who may still have and use 32-bit third-party
software, or peripheral drives (old printer/scanners, etc.)
Your older Mac could run these macOS:
Mojave 10.14.6, Catalina 10.15.7, should be willing, & able.. Big Sur 11.x
maybe on-the-fence for fringe models; might need additional upgrade
in hardware. Certain older Macs could benefit by upgrade to hard drive
with replacement to a solid-state-drive (SSD). Memory and storage both
could help an older mac cope with tasks; beyond browsing.
Not all products may qualify toward trade-in, some may be recycled free.
Should the older Mac portable have depreciated values, or conditionally
have no significant trade-in values, the offer to recycle those models free.
• Apple Trade In* - Apple
https://www.apple.com/shop/trade-in
"Apple Trade-In lets you recycle Apple devices (including devices from
Apple-owned brands) at any Apple Store, and on apple.com, for free."
• Apple Store - Find a Store - Apple
https://www.apple.com/retail/
In some instances, your older Mac may find a new home. In any case
be sure to make backups of your Mac's content ~ to external USB drive
with Time Machine; even if you aren't quite ready to upgrade/trade.
You've a few choices; keep Mac; or ready to trade, or sell old Mac..
(A process outlined in detail in Support site) and back up the Mac.
• What to do before you sell, give away, or trade in your Mac - Apple Support
https://support.apple.com/en-us/HT201065
Good luck & happy trails! ☺︎