Using HELOC for primary rehab or investing in a new property

My wife and I are looking to start investing this year. Currently we're working on reaching a savings goal before we make a move, but we're trying to nail down a strategy to pursue. Using a HELOC is one option we're considering. Our HELOC amount would be roughly $25k-$27k. Here are the options we're considering.

1) Use a HELOC to update our current primary residence (SFR), sell it, and use profits for next property.

2) Move into a new property (probably MFR), using primary residence as a rental in current condition. Use a HELOC as either a down payment or rehab budget on the new property, and use OPM for whichever other piece we need.

3) Stay in primary residence and update it with HELOC; use only OPM for new property.

Thanks for any advice!