Some things to think about...

Are you going to have internet in the future and will you need to use one of the three drops you are talking about?

1.) F connectors

PPC EX6XLPLUS RG-6 Quad Seal Outdoor/Indoor Compression Connector, (Pack of 50) + Qty 5: F-81 F-Type PPC CF81GHZC 3GHZ Coax Barrels Coupler https://www.amazon.com/dp/B00FNX8V3C/ref=cm_sw_r_cp_apa_1xwrAbDJJSWMZ

2.) You can use a knife or wire stripper, but you want to make sure they are done right

I'd get one of these to save time

BlueCosto Wire Stripper Cutter for Round / Flat UTP Cat5 Cat6 Coax Coaxial Cable Stripping Universal Tool https://www.amazon.com/dp/B00NXJJTVQ/ref=cm_sw_r_cp_apa_wAwrAbC7E5B7S

3.) Read directions for this. Think about if you'll be adding lines in the future

PCT MA28PN RF Amplifier Passive Return CATV Amp 8-Ports https://www.amazon.com/dp/B000WDR94U/ref=cm_sw_r_cp_apa_5DwrAbEM6MWK0

Is the splitter passive (non-powered) or a distribution amplifier (powered splitter)? If it's the former then you could be suffering from splitter signal degradation and would need a preamp (Winegard LNA-200 or RCATVPRAMP1R) or replace the splitter with a distribution amplifier.

You might use a coax coupler and connect the antenna directly to the TV at the splitter location. If reception improves then you know it's the splitter.