So, you somehow think its practical for someone to join ten clubs? Either about different things of about one thing?
I'm in two walking clubs, that's hard enough to manage.
Also, right now, most clubs can't operate. Walking is back on next week but only in groups of six. I've just looked and it's all women on my next walk, except the walk leader who I know reasonably well and definitely don't fancy.
"Join clubs" is what smug marrieds say to single people.
In response to the OP - the dating apps are just bits of software, so it's best to choose the one whose platform and functionality suit you best. You'll pretty much find all the same men on all the apps anyway.
Some work by "matching" (Bumble, Tinder) and you can't chat until you match. Others have a more open messaging system (POF, Match - I think) which is where you get bombarded with idiots and find you have a full mailbox all the time. I prefer the former type. I've never used Tinder though.
She'll need to steel herself, it can be pretty soul destroying if you take it too seriously. I tend to view it as a way to meet and chat to people. Nothing is real until you've had the first meet up with someone.