Hello Jessie,
Answering to your questions:
1. What will make me more valuable? Certs? Experience? Multi-Vendor knowledge?
A = For me: knowledge. If you have the right knowledge no matter how many years or certifications do you have, both are a plus. There are many young people that maybe have not many years of experience but have more knowledge than others. On the other hand the certifications are a probe of your knowledge but if you do not have money to pay this you can still demonstrate your knowledge in other ways (accepting short thecnical test from your clients for example). Multi-Vendor knowledge is good but it is something I think you maybe will handle on the march.
2. Where should I find side gigs? Upwork?
A = www.freelancer.com www.workana.com and Upwork
3. Is there anyway Can I get access to more Cisco tools and resources like a Partner?
A = No, I do not think that. You can create a Cisco account in order to gain access for certains tools but there are many Cisco resources specially for partners, and if you need an special support from a TAC Engineer you need a service contract (related to the device having the trouble) associated to you profile .
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Hope this can be helpful to you.