Did you work with any real estate professionals (agents, lenders, etc.) that you'd recommend to others?

My recommendation is get a self directed IRA and have the real estate be owned by your IRAYeah,  I have heard a lot about the self directed IRA.  

I have investing a bit in REITS so that's something I just learned about recently.Regarding Peer-to-Peer Lending or CrowdfundinIs any any platform you have experience with that you could recommend?

I recommend beginning with a turnkey property.

Hopefully, you find it helpful and qualifies us to assist you with your goals:)---------------------------------------------------------------------------------------------------Recommend you first figure out the property Class you want to invest in, THEN figure out the corresponding location to invest in.Property Class will typically dictate the Class of tenant you get, which greatly IMPACTS rental income stability and property maintenance/damage by tenants.If you apply Class A assumptions to a Class B or C purchase, your expectations won’t be met and it may be a financial disaster.If you buy/renovate a property in Class D area to Class A standards, what quality of tenant will you get?

.- I recommend avoiding condos. 

Did you work with any real estate professionals (agents, lenders, etc.) that you'd recommend to others?

Can you recommend a management software for managing 100+ doors I tried Cozy.

Also, can anyone recommend a reliable company for this?

I recommend you budget 5% of the gross rent (for the whole place, even what the rent would be if you were living in it as a tenant) for repairs and 5% for capital expenditures.