formal recruitment

I mean...you will most likely be split up from your friends during recruitment anyway. Every experience is different and you will most likely end up going to different houses and you don't necessarily want your friend's opinions affecting your choices. Choose what is best for YOU. So in short, no, it's fine to go by yourself. Make friends with the PNMs around you, especially after each cut, because they could end up being your sisters! :)

In my opinion it is better to go through recruitment alone. It lallows you make your own opinions and to make new friends. Also, something almost every house will ask you is, "why did you decide to rush?" Rushing because you really want to or to make friends is so much better than doing it because other ppl told you 2.