Investing profits from one sale to fund another purchase

[Justin Petrides]

I currently own a small single family house outright in PA . I’m looking to sell this and purchase a multi-unit ( up to 4 units ) in Florida . I will be living in one of the units . I’ll be working with approximately $100k . I’m looking at properties in the range of $200-300k. I would like to only put 20% down and save the rest of the money , possibly to use later for another investment property. 1-How long do I have to wait to acquire another mortgage on another multi - unit? 2-Do I Have to spend all my $100K to avoId paying capital gains tax? 3- should I put more $ down on the multi-unit to avoid paying more taxes on my gains ? 4-If I was to open an LLC to manage the property could I use a portion of the profits from the single family for the business. 5- I’m new to this and I’m trying to find the smartest way to move this money and pay the least amount of taxes but also maximize my profits .