Hi and welcome!
Please get a female companion! Age is less important than mutual acceptance and liking; guinea pigs of either gender can be rebonded at all ages. Any baby is desperate for company and not able to challenge for the hierarchy. It all depends on how much dominance behaviour you get from the other sow; it is something you have to brace yourself for.
Please be aware that you may need to conduct a quarantine and that in any case you need do introductions properly if you rehome from freeads.
In any case, please re-check the gender before you put any guinea pigs together. Mis-sexing is not at all uncommon.
You may find these guides here helpful:
Importance Of Quarantine
" Starter Kit" Of Information Threads For New Owners
(also contains guides on companionship, behaviour and introductions as well as a sexing link, as well as links to good standard recommended rescues with mandatory quarantine)
Since we have members from all over the world, we find it very helpful if you please added your country, state/province or UK county to your details, so we can tailor any advice to what is available and relevant for where you are. Click on your username on the top bar, then go to personal details and scroll down to location. Thank you!