There are a lot of pieces to this, but I'm glad you're asking. This can absolutely be done DIY, but you're right, it's time consuming and there are a lot of pieces to keep track of. An agency will already have a process in place to manage these different pieces for you. My agency specializes in PR, branding and digital marketing, so check us out if hiring an agency is an option for you - https://redchalkstudios.com/.
For a DIY approach:
- Instagram campaigns are managed using Facebook Ads platform. As a marketer, that's a nice feature, I can manage both FB and IG campaigns in one place. LinkedIn has it's own ads platform called Campaign Manager (https://www.linkedin.com/ad-beta/accounts).
- For blogs, it's best to be consistent, but don't write for the sake of writing. Make sure to plan a content schedule that you can keep up with. For blog ideas, there are some awesome resources. SEMRush has a content idea generation feature, there are sites like AnswerThePublic where you can enter a keyword and it will populate common questions around that subject that you can answer with your posts.
- Networking is something I'm personally working on, too. Each Monday I log into Meetup, Eventbrite and Facebook and search their "Business" categories for networking events.
- Attending these networking events is also a great way to meet the event coordinators and introduce yourself as a possible event host and speaker. Also, if you do a Google search for "call for speakers" you'll find conferences/summits that are looking for speakers for their events.
- Producing in-person events takes some planning. Who is your target audience? What are the problems they face with their business that you can coach them on? How big do you want the event? And how much do you want to charge? Where are you going to have it? There are a lot of logistics. Take notes during the events you attend as to what you like about how the event is held before you start planning your own.
Hope this helps!